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da Silva BC, Sadre Momtaz Z, Monroy E, Okuno H, Rouviere JL, Cooper D, Den Hertog MI. Assessment of Active Dopants and p-n Junction Abruptness Using In Situ Biased 4D-STEM. NANO LETTERS 2022; 22:9544-9550. [PMID: 36442685 DOI: 10.1021/acs.nanolett.2c03684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A key issue in the development of high-performance semiconductor devices is the ability to properly measure active dopants at the nanometer scale. In a p-n junction, the abruptness of the dopant profile around the metallurgical junction directly influences the electric field. Here, a contacted nominally symmetric and highly doped (NA = ND = 9 × 1018 cm-3) silicon p-n specimen is studied through in situ biased four-dimensional scanning transmission electron microscopy (4D-STEM). Measurements of electric field, built-in voltage, depletion region width, and charge density are combined with analytical equations and finite-element simulations in order to evaluate the quality of the junction interface. It is shown that all the junction parameters measured are compatible with a linearly graded junction. This hypothesis is also consistent with the evolution of the electric field with bias as well as off-axis electron holography data. These results demonstrate that in situ biased 4D-STEM can allow a better understanding of the electrostatics of semiconductor p-n junctions with nm-scale resolution.
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Affiliation(s)
| | | | - Eva Monroy
- Université Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, F-38000Grenoble, France
| | - Hanako Okuno
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, F-38000Grenoble, France
| | - Jean-Luc Rouviere
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, F-38000Grenoble, France
| | - David Cooper
- Université Grenoble Alpes, CEA-LETI, F-38000Grenoble, France
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2
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Lahreche A, Babichev AV, Beggah Y, Tchernycheva M. Modeling of the electron beam induced current signal in nanowires with an axial p-n junction. NANOTECHNOLOGY 2022; 33:395701. [PMID: 35700698 DOI: 10.1088/1361-6528/ac7887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
A tridimensional mathematical model to calculate the electron beam induced current (EBIC) of an axial p-n nanowire junction is proposed. The effect of the electron beam and junction parameters on the distribution of charge carriers and on the collected EBIC current is reported. We demonstrate that the diffusion of charge carriers within the wire is strongly influenced by the electrical state of its lateral surface which is characterized by a parameter called surface recombination velocity (vr). When the surface recombination is weak (i.e. lowvrvalue), the diffusion of charge carriers occurs in one dimension (1D) along the wire axis, and, in this case, the use of bulk EBIC models to extract the diffusion length (L) of charge carriers is justified. However, when the surface effects are strong (i.e. highvrvalues), the diffusion happens in three dimensions (3D). In this case, the EBIC profiles depend onvrvalue and two distinct cases can be defined. If theLis larger than the nanowire radius (ra), the EBIC profiles show a strong dependency with this parameter. This gives evidence that the recombination of generated carriers on the surface throughvris the dominant process. In this situation, a decrease of two orders of magnitude in the EBIC profiles computed with a high and a lowvrvalue is observed in neutral regions of the junction. For the case ofLsmaller thanrathe dependency of the EBIC profiles on thevris weak, and the prevalent recombination mechanism is the bulk recombination process.
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Affiliation(s)
- Abderrezak Lahreche
- Department de technologie, Université A.Mira de Bejaia, 6000 Bejaia, Algérie
- Laboratoire Matériaux: Elaborations-Propriétés - Applications (LMEPA), Université Jijel, 18000 Jijel, Algérie
| | - Andrey V Babichev
- Saint Petersburg Electrotechnical University "LETI", 197376 St. Petersburg, Russia
- ITMO University, 197101 St. Petersburg, Russia
| | - Yamina Beggah
- Laboratoire Matériaux: Elaborations-Propriétés - Applications (LMEPA), Université Jijel, 18000 Jijel, Algérie
| | - Maria Tchernycheva
- Centre de Nanosciences et de Nanotechnologies (C2N), CNRS UMR 9001, University Paris-Saclay, F-91120 Palaiseau, France
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3
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Conlan AP, Luong MA, Gentile P, Moldovan G, Den Hertog MI, Monroy E, Cooper D. Thermally propagated Al contacts on SiGe nanowires characterized by electron beam induced current in a scanning transmission electron microscope. NANOTECHNOLOGY 2021; 33:035712. [PMID: 34633307 DOI: 10.1088/1361-6528/ac2e73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
Here, we use electron beam induced current (EBIC) in a scanning transmission electron microscope to characterize the structure and electronic properties of Al/SiGe and Al/Si-rich/SiGe axial nanowire heterostructures fabricated by thermal propagation of Al in a SiGe nanowire. The two heterostructures behave as Schottky contacts with different barrier heights. From the sign of the beam induced current collected at the contacts, the intrinsic semiconductor doping is determined to be n-type. Furthermore, we find that the silicon-rich double interface presents a lower barrier height than the atomically sharp SiGe/Al interface. With an applied bias, the Si-rich region delays the propagation of the depletion region and presents a reduced free carrier diffusion length with respect to the SiGe nanowire. This behaviour could be explained by a higher residual doping in the Si-rich area. These results demonstrate that scanning transmission electron microscopy EBIC is a powerful method for mapping and quantifying electric fields in micrometer- and nanometer-scale devices.
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Affiliation(s)
- Aidan P Conlan
- Univ. Grenoble Alpes, CEA-LETI, F-38000 Grenoble, France
| | - Minh Anh Luong
- Univ. Grenoble Alpes, CNRS-Institut Néel, 25 Avenue des Martyrs, F-38000 Grenoble, France
| | - Pascal Gentile
- Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 17 av. des Martyrs, F-38000 Grenoble, France
| | - Grigore Moldovan
- Point Electronic GmbH, Erich-Neuss-Weg 15, D-06120 Halle (Saale), Germany
| | - Martien I Den Hertog
- Univ. Grenoble Alpes, CNRS-Institut Néel, 25 Avenue des Martyrs, F-38000 Grenoble, France
| | - Eva Monroy
- Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 17 av. des Martyrs, F-38000 Grenoble, France
| | - David Cooper
- Univ. Grenoble Alpes, CEA-LETI, F-38000 Grenoble, France
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4
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Stretchable Transparent Light-Emitting Diodes Based on InGaN/GaN Quantum Well Microwires and Carbon Nanotube Films. NANOMATERIALS 2021; 11:nano11061503. [PMID: 34200237 PMCID: PMC8230151 DOI: 10.3390/nano11061503] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/13/2021] [Accepted: 06/01/2021] [Indexed: 01/30/2023]
Abstract
We propose and demonstrate both flexible and stretchable blue light-emitting diodes based on core/shell InGaN/GaN quantum well microwires embedded in polydimethylsiloxane membranes with strain-insensitive transparent electrodes involving single-walled carbon nanotubes. InGaN/GaN core-shell microwires were grown by metal-organic vapor phase epitaxy, encapsulated into a polydimethylsiloxane film, and then released from the growth substrate. The fabricated free-standing membrane of light-emitting diodes with contacts of single-walled carbon nanotube films can stand up to 20% stretching while maintaining efficient operation. Membrane-based LEDs show less than 15% degradation of electroluminescence intensity after 20 cycles of stretching thus opening an avenue for highly deformable inorganic devices.
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5
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Fabrication of GaN nano-towers based self-powered UV photodetector. Sci Rep 2021; 11:10859. [PMID: 34035437 PMCID: PMC8149650 DOI: 10.1038/s41598-021-90450-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/12/2021] [Indexed: 11/13/2022] Open
Abstract
The fabrication of unique taper-ended GaN-Nanotowers structure based highly efficient ultraviolet photodetector is demonstrated. Hexagonally stacked, single crystalline GaN nanocolumnar structure (nanotowers) grown on AlN buffer layer exhibits higher photocurrent generation due to high quality nanotowers morphology and increased surface/volume ratio which significantly enhances its responsivity upon ultraviolet exposure leading to outstanding performance from the developed detection device. The fabricated detector display low dark current (~ 12 nA), high ILight/IDark ratio (> 104), fast time-correlated transient response (~ 433 µs) upon ultraviolet (325 nm) illumination. A high photoresponsivity of 2.47 A/W is achieved in self-powered mode of operation. The reason behind such high performance could be attributed to built-in electric field developed from a difference in Schottky barrier heights will be discussed in detail. While in photoconductive mode, the responsivity is observed to be 35.4 A/W @ − 3 V along with very high external quantum efficiency (~ 104%), lower noise equivalent power (~ 10–13 WHz−1/2) and excellent UV–Vis selectivity. Nanotower structure with lower strain and dislocations as well as reduced trap states cumulatively contributed to augmented performance from the device. The utilization of these GaN-Nanotower structures can potentially be useful towards the fabrication of energy-efficient ultraviolet photodetectors.
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6
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Lassiaz T, Tchoulfian P, Donatini F, Brochet J, Parize R, Jacopin G, Pernot J. Nanoscale Dopant Profiling of Individual Semiconductor Wires by Capacitance-Voltage Measurement. NANO LETTERS 2021; 21:3372-3378. [PMID: 33825480 DOI: 10.1021/acs.nanolett.0c04491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Developing nanoscale electrical characterization techniques adapted to three-dimensional (3D) geometry is essential for optimization of the epitaxial structure and doping process of nano- and microwires. In this paper, we demonstrate the assessment of the depletion width as well as the doping profile at the nanoscale of individual microwire core-shell light-emitting devices by capacitance-voltage measurements. A statistical study carried out on single wires shows the consistency of the doping profile values measured for individual microwires compared to assemblies of hundreds of wires processed on the same sample. The robustness of this method is then demonstrated on four epitaxial structures with different growth and doping conditions. Finally, electron-beam-induced current and secondary electron profiles are used to validate the depletion region width and the position in the core-shell structure.
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Affiliation(s)
- Timothée Lassiaz
- Aledia, F-38130 Echirolles, France
- Univ Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | | | - Fabrice Donatini
- Univ Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | | | | | - Gwénolé Jacopin
- Univ Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - Julien Pernot
- Univ Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
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7
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Saket O, Wang J, Amador-Mendez N, Morassi M, Kunti A, Bayle F, Collin S, Jollivet A, Babichev A, Sodhi T, Harmand JC, Julien FH, Gogneau N, Tchernycheva M. Investigation of the effect of the doping order in GaN nanowire p-n junctions grown by molecular-beam epitaxy. NANOTECHNOLOGY 2021; 32:085705. [PMID: 33171444 DOI: 10.1088/1361-6528/abc91a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We analyse the electrical and optical properties of single GaN nanowire p-n junctions grown by plasma-assisted molecular-beam epitaxy using magnesium and silicon as doping sources. Different junction architectures having either a n-base or a p-base structure are compared using optical and electrical analyses. Electron-beam induced current (EBIC) microscopy of the nanowires shows that in the case of a n-base p-n junction the parasitic radial growth enhanced by the magnesium (Mg) doping leads to a mixed axial-radial behaviour with strong wire-to-wire fluctuations of the junction position and shape. By reverting the doping order p-base p-n junctions with a purely axial well-defined structure and a low wire-to-wire dispersion are achieved. The good optical quality of the top n nanowire segment grown on a p-doped stem is preserved. A hole concentration in the p-doped segment exceeding 1018 cm-3 was extracted from EBIC mapping and photoluminescence analyses. This high concentration is reached without degrading the nanowire morphology.
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Affiliation(s)
- Omar Saket
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Junkang Wang
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Nuño Amador-Mendez
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Martina Morassi
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Arup Kunti
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Fabien Bayle
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Stéphane Collin
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Arnaud Jollivet
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | | | - Tanbir Sodhi
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Jean-Christophe Harmand
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - François H Julien
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Noelle Gogneau
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
| | - Maria Tchernycheva
- Centre de Nanosciences et de Nanotechnologies (C2N), UMR 9001 CNRS, Université Paris Saclay, 91120 Palaiseau, France
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8
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Hill JW, Hill CM. Directly visualizing carrier transport and recombination at individual defects within 2D semiconductors. Chem Sci 2021; 12:5102-5112. [PMID: 34163749 PMCID: PMC8179556 DOI: 10.1039/d0sc07033e] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 02/08/2021] [Indexed: 12/13/2022] Open
Abstract
Two-dimensional semiconductors (2DSCs) are promising materials for a wide range of optoelectronic applications. While the fabrication of 2DSCs with thicknesses down to the monolayer limit has been demonstrated through a variety of routes, a robust understanding of carrier transport within these materials is needed to guide the rational design of improved practical devices. In particular, the influence of different types of structural defects on transport is critical, but difficult to interrogate experimentally. Here, a new approach to visualizing carrier transport within 2DSCs, Carrier Generation-Tip Collection Scanning Electrochemical Cell Microscopy (CG-TC SECCM), is described which is capable of providing information at the single-defect level. In this approach, carriers are locally generated within a material using a focused light source and detected as they drive photoelectrochemical reactions at a spatially-offset electrolyte interface created through contact with a pipet-based probe, allowing carrier transport across well-defined, µm-scale paths within a material to be directly interrogated. The efficacy of this approach is demonstrated through studies of minority carrier transport within mechanically-exfoliated n-type WSe2 nanosheets. CG-TC SECCM imaging experiments carried out within pristine basal planes revealed highly anisotropic hole transport, with in-plane and out-of-plane hole diffusion lengths of 2.8 µm and 5.8 nm, respectively. Experiments were also carried out to probe recombination across individual step edge defects within n-WSe2 which suggest a significant surface charge (∼5 mC m-2) exists at these defects, significantly influencing carrier transport. Together, these studies demonstrate a powerful new approach to visualizing carrier transport and recombination within 2DSCs, down to the single-defect level.
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Affiliation(s)
- Joshua W Hill
- Department of Chemistry, University of Wyoming, 1000 E University Ave Laramie WY 82071 USA
| | - Caleb M Hill
- Department of Chemistry, University of Wyoming, 1000 E University Ave Laramie WY 82071 USA
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9
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Influence of Growth Polarity Switching on the Optical and Electrical Properties of GaN/AlGaN Nanowire LEDs. ELECTRONICS 2020. [DOI: 10.3390/electronics10010045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
For the development and application of GaN-based nanowire structures, it is crucial to understand their fundamental properties. In this work, we provide the nano-scale correlation of the morphological, electrical, and optical properties of GaN/AlGaN nanowire light emitting diodes (LEDs), observed using a combination of spatially and spectrally resolved cathodoluminescence spectroscopy and imaging, electron beam-induced current microscopy, the nano-probe technique, and scanning electron microscopy. To complement the results, the photo- and electro-luminescence were also studied. The interpretation of the experimental data was supported by the results of numerical simulations of the electronic band structure. We characterized two types of nanowire LEDs grown in one process, which exhibit top facets of different shapes and, as we proved, have opposite growth polarities. We show that switching the polarity of nanowires (NWs) from the N- to Ga-face has a significant impact on their optical and electrical properties. In particular, cathodoluminescence studies revealed quantum wells emissions at about 3.5 eV, which were much brighter in Ga-polar NWs than in N-polar NWs. Moreover, the electron beam-induced current mapping proved that the p–n junctions were not active in N-polar NWs. Our results clearly indicate that intentional polarity inversion between the n- and p-type parts of NWs is a potential path towards the development of efficient nanoLED NW structures.
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10
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Grenier V, Finot S, Jacopin G, Bougerol C, Robin E, Mollard N, Gayral B, Monroy E, Eymery J, Durand C. UV Emission from GaN Wires with m-Plane Core-Shell GaN/AlGaN Multiple Quantum Wells. ACS APPLIED MATERIALS & INTERFACES 2020; 12:44007-44016. [PMID: 32894670 DOI: 10.1021/acsami.0c08765] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The present work reports high-quality nonpolar GaN/Al0.6Ga0.4N multiple quantum wells (MQWs) grown in core-shell geometry by metal-organic vapor-phase epitaxy on the m-plane sidewalls of c̅-oriented hexagonal GaN wires. Optical and structural studies reveal ultraviolet (UV) emission originating from the core-shell GaN/AlGaN MQWs. Tuning the m-plane GaN QW thickness from 4.3 to 0.7 nm leads to a shift of the emission from 347 to 292 nm, consistent with Schrödinger-Poisson calculations. The evolution of the luminescence with temperature displays signs of strong localization, especially for samples with thinner GaN QWs and no evidence of quantum-confined Stark effect, as expected for nonpolar m-plane surfaces. The internal quantum efficiency derived from the photoluminescence (PL) intensity ratio at low and room temperatures is maximum (∼7.3% measured at low power excitation) for 2.6 nm thick quantum wells, emitting at 325 nm, and shows a large drop for thicker QWs. An extensive study of the PL quenching with temperature is presented. Two nonradiative recombination paths are activated at different temperatures. The low-temperature path is found to be intrinsic to the heterostructure, whereas the process that dominates at high temperature depends on the QW thickness and is strongly enhanced for QWs larger than 2.6 nm, causing a rapid decrease in the internal quantum efficiency.
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Affiliation(s)
- Vincent Grenier
- Université Grenoble Alpes, CEA, IRIG, PHELIQS, NPSC, 38000 Grenoble, France
| | - Sylvain Finot
- Université Grenoble Alpes, CNRS, Institut Néel, 38000 Grenoble, France
| | - Gwénolé Jacopin
- Université Grenoble Alpes, CNRS, Institut Néel, 38000 Grenoble, France
| | | | - Eric Robin
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, 38000 Grenoble, France
| | - Nicolas Mollard
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, 38000 Grenoble, France
| | - Bruno Gayral
- Université Grenoble Alpes, CEA, IRIG, PHELIQS, NPSC, 38000 Grenoble, France
| | - Eva Monroy
- Université Grenoble Alpes, CEA, IRIG, PHELIQS, NPSC, 38000 Grenoble, France
| | - Joël Eymery
- Université Grenoble Alpes, CEA, IRIG, MEM, NRS, 38000 Grenoble, France
| | - Christophe Durand
- Université Grenoble Alpes, CEA, IRIG, PHELIQS, NPSC, 38000 Grenoble, France
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11
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Goswami L, Aggarwal N, Krishna S, Singh M, Vashishtha P, Singh SP, Husale S, Pandey R, Gupta G. Au-Nanoplasmonics-Mediated Surface Plasmon-Enhanced GaN Nanostructured UV Photodetectors. ACS OMEGA 2020; 5:14535-14542. [PMID: 32596591 PMCID: PMC7315566 DOI: 10.1021/acsomega.0c01239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/02/2020] [Indexed: 05/03/2023]
Abstract
The nanoplasmonic impact of chemically synthesized Au nanoparticles (Au NPs) on the performance of GaN nanostructure-based ultraviolet (UV) photodetectors is analyzed. The devices with uniformly distributed Au NPs on GaN nanostructures (nanoislands and nanoflowers) prominently respond toward UV illumination (325 nm) in both self-powered as well as photoconductive modes of operation and have shown fast and stable time-correlated response with significant enhancement in the performance parameters. A comprehensive analysis of the device design, laser power, and bias-dependent responsivity and response time is presented. The fabricated Au NP/GaN nanoflower-based device yields the highest photoresponsivity of ∼ 380 mA/W, detectivity of ∼ 1010 jones, reduced noise equivalent power of ∼ 5.5 × 10-13 W Hz-1/2, quantum efficiency of ∼ 145%, and fast response/recovery time of ∼40 ms. The report illustrates the mechanism where light interacts with the chemically synthesized nanoparticles guided by the surface plasmon to effectively enhance the device performance. It is observed that the Au NP-stimulated local surface plasmon resonance effect and reduced channel resistance contribute to the augmented performance of the devices. Further, the decoration of low-dimensional Au NPs on GaN nanostructures acts as a detection enhancer with a fast recovery time and paves the way toward the realization of energy-efficient optoelectronic device applications.
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Affiliation(s)
- Lalit Goswami
- Department
of Electronics and Communication Engineering, Delhi Technological University, New Delhi 110042, India
- CSIR-National
Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India
| | - Neha Aggarwal
- CSIR-National
Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India
- Academy
of Scientific and Innovative Research, CSIR-HRDC Campus, Ghaziabad, Uttar Pradesh 201002, India
| | - Shibin Krishna
- CSIR-National
Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India
- Academy
of Scientific and Innovative Research, CSIR-HRDC Campus, Ghaziabad, Uttar Pradesh 201002, India
| | - Manjri Singh
- CSIR-National
Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India
| | - Pargam Vashishtha
- CSIR-National
Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India
- Academy
of Scientific and Innovative Research, CSIR-HRDC Campus, Ghaziabad, Uttar Pradesh 201002, India
| | - Surinder Pal Singh
- CSIR-National
Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India
| | - Sudhir Husale
- CSIR-National
Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India
| | - Rajeshwari Pandey
- Department
of Electronics and Communication Engineering, Delhi Technological University, New Delhi 110042, India
| | - Govind Gupta
- CSIR-National
Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012, India
- Academy
of Scientific and Innovative Research, CSIR-HRDC Campus, Ghaziabad, Uttar Pradesh 201002, India
- .
Phone: +91-1145609503
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12
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Kapoor A, Finot S, Grenier V, Robin E, Bougerol C, Bleuse J, Jacopin G, Eymery J, Durand C. Role of Underlayer for Efficient Core-Shell InGaN QWs Grown on m-plane GaN Wire Sidewalls. ACS APPLIED MATERIALS & INTERFACES 2020; 12:19092-19101. [PMID: 32208628 DOI: 10.1021/acsami.9b19314] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Different types of buffer layers such as InGaN underlayer (UL) and InGaN/GaN superlattices are now well-known to significantly improve the efficiency of c-plane InGaN/GaN-based light-emitting diodes (LEDs). The present work investigates the role of two different kinds of pregrowth layers (low In-content InGaN UL and GaN UL namely "GaN spacer") on the emission of the core-shell m-plane InGaN/GaN single quantum well (QW) grown around Si-doped c̅-GaN microwires obtained by silane-assisted metal organic vapor phase epitaxy. According to photo- and cathodoluminescence measurements performed at room temperature, an improved efficiency of light emission at 435 nm with internal quantum efficiency >15% has been achieved by adding a GaN spacer prior to the growth of QW. As revealed by scanning transmission electron microscopy, an ultrathin residual layer containing Si located at the wire sidewall surfaces favors the formation of high density of extended defects nucleated at the first InGaN QW. This contaminated residual incorporation is buried by the growth of the GaN spacer and avoids the structural defect formation, therefore explaining the improved optical efficiency. No further improvement is observed by adding the InGaN UL to the structure, which is confirmed by comparable values of the effective carrier lifetime estimated from time-resolved experiments. Contrary to the case of planar c-plane QW where the improved efficiency is attributed to a strong decrease of point defects, the addition of an InGaN UL seems to have no influence in the case of radial m-plane QW.
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Affiliation(s)
- Akanksha Kapoor
- Université Grenoble Alpes, CEA, IRIG, PHELIQS, NPSC, Grenoble 38000, France
| | - Sylvain Finot
- Université Grenoble Alpes, CNRS, Institut Néel, Grenoble 38000, France
| | - Vincent Grenier
- Université Grenoble Alpes, CEA, IRIG, PHELIQS, NPSC, Grenoble 38000, France
| | - Eric Robin
- Université Grenoble Alpes, CEA, IRIG, MEM, LEMMA, Grenoble 38000, France
| | | | - Joel Bleuse
- Université Grenoble Alpes, CEA, IRIG, PHELIQS, NPSC, Grenoble 38000, France
| | - Gwénolé Jacopin
- Université Grenoble Alpes, CNRS, Institut Néel, Grenoble 38000, France
| | - Joël Eymery
- Université Grenoble Alpes, CEA, IRIG, MEM, NRS, Grenoble 38000, France
| | - Christophe Durand
- Université Grenoble Alpes, CEA, IRIG, PHELIQS, NPSC, Grenoble 38000, France
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Saket O, Himwas C, Piazza V, Bayle F, Cattoni A, Oehler F, Patriarche G, Travers L, Collin S, Julien FH, Harmand JC, Tchernycheva M. Nanoscale electrical analyses of axial-junction GaAsP nanowires for solar cell applications. NANOTECHNOLOGY 2020; 31:145708. [PMID: 31846937 DOI: 10.1088/1361-6528/ab62c9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Axial p-n and p-i-n junctions in GaAs0.7P0.3 nanowires are demonstrated and analyzed using electron beam induced current microscopy. Organized self-catalyzed nanowire arrays are grown by molecular beam epitaxy on nanopatterned Si substrates. The nanowires are doped using Be and Si impurities to obtain p- and n-type conductivity, respectively. A method to determine the doping type by analyzing the induced current in the vicinity of a Schottky contact is proposed. It is demonstrated that for the applied growth conditions using Ga as a catalyst, Si doping induces an n-type conductivity contrary to the GaAs self-catalyzed nanowire case, where Si was reported to yield a p-type doping. Active axial nanowire p-n junctions having a homogeneous composition along the axis are synthesized and the carrier concentration and minority carrier diffusion lengths are measured. To the best of our knowledge, this is the first report of axial p-n junctions in self-catalyzed GaAsP nanowires.
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Affiliation(s)
- Omar Saket
- Centre de Nanosciences et de Nanotechnologies, UMR 9001 CNRS, Univ. Paris Sud, Univ. Paris-Saclay, 10 Boulevard Thomas Gobert, F-91120 Palaiseau Cedex, France
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14
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Siladie AM, Jacopin G, Cros A, Garro N, Robin E, Caliste D, Pochet P, Donatini F, Pernot J, Daudin B. Mg and In Codoped p-type AlN Nanowires for pn Junction Realization. NANO LETTERS 2019; 19:8357-8364. [PMID: 31724873 DOI: 10.1021/acs.nanolett.9b01394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Efficient, mercury-free deep ultraviolet (DUV) light-emitting diodes (LEDs) are becoming a crucial challenge for many applications such as water purification. For decades, the poor p-type doping and difficult current injection of Al-rich AlGaN-based DUV LEDs have limited their efficiency and therefore their use. We present here the significant increase in AlN p-doping thanks to Mg/In codoping, which leads to an order of magnitude higher Mg solubility limit in AlN nanowires (NWs). Optimal electrical activation of acceptor impurities has been further achieved by electron irradiation, resulting in tunnel conduction through the AlN NW p-n junction. The proposed theoretical scenario to account for enhanced Mg incorporation involves an easy ionization of In-vacancy complex associated with a negative charging of Mg in In vicinity. This leads to favored incorporation of negatively charged Mg into the AlN matrix, opening the path to the realization of highly efficient NW-based LEDs in the DUV range.
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Affiliation(s)
| | - Gwénolé Jacopin
- Grenoble INP, Institut Néel , University Grenoble Alpes, CNRS , 38000 Grenoble , France
| | - Ana Cros
- Institute of Materials Science , Universidad de Valencia , Valencia , Spain
| | - Nuria Garro
- Institute of Materials Science , Universidad de Valencia , Valencia , Spain
| | - Eric Robin
- IRIG-MEM, LEMMA , University Grenoble Alpes, CEA , F-38000 Grenoble , France
| | - Damien Caliste
- IRIG-MEM, L-SIM , University Grenoble Alpes, CEA , F-38000 Grenoble , France
| | - Pascal Pochet
- IRIG-MEM, L-SIM , University Grenoble Alpes, CEA , F-38000 Grenoble , France
| | - Fabrice Donatini
- Grenoble INP, Institut Néel , University Grenoble Alpes, CNRS , 38000 Grenoble , France
| | - Julien Pernot
- Grenoble INP, Institut Néel , University Grenoble Alpes, CNRS , 38000 Grenoble , France
| | - Bruno Daudin
- IRIG-PHELIQS, NPSC , University Grenoble Alpes, CEA , 38000 Grenoble , France
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15
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Sankaranarayanan S, Kandasamy P, Krishnan B. Catalytic Growth of Gallium Nitride Nanowires on Wet Chemically Etched Substrates by Chemical Vapor Deposition. ACS OMEGA 2019; 4:14772-14779. [PMID: 31552316 PMCID: PMC6751544 DOI: 10.1021/acsomega.9b01284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 08/22/2019] [Indexed: 06/10/2023]
Abstract
Growth of gallium nitride nanowires on etched sapphire and GaN substrates using binary catalytic alloy were investigated by manipulating the growth time and precursor-to-substrate distance. The variations in behavior at different growth conditions were observed using X-ray diffractometer, Raman spectroscopy, X-ray photoelectron spectroscopy, cathodoluminescence spectroscopy, optical microscopy, atomic force microscopy, and scanning electron microscopy. It was noticed that, in respect of both the substrates, when growth time and/or precursor-to-substrate distance is increased, thickness of the nanowires around the etch pits remains unaltered, but there is variation in the density of nanowires. In addition, formation of gallium nitride microwires within the etch pits was also observed on etched sapphire substrates. Similarly, the thickness and density of the microwires were found to increase with increase in growth time and decrease with increase in precursor-to-substrate distance. The dimensionality scaling of gallium nitride was found to have a positive effect in improving the luminescence property and band gap of the grown nanowires. This method of nanowire growth can be helpful in increasing the probability of multiple reflections in the materials which makes them a suitable candidate for optoelectronic devices.
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16
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Barrigón E, Heurlin M, Bi Z, Monemar B, Samuelson L. Synthesis and Applications of III-V Nanowires. Chem Rev 2019; 119:9170-9220. [PMID: 31385696 DOI: 10.1021/acs.chemrev.9b00075] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Low-dimensional semiconductor materials structures, where nanowires are needle-like one-dimensional examples, have developed into one of the most intensely studied fields of science and technology. The subarea described in this review is compound semiconductor nanowires, with the materials covered limited to III-V materials (like GaAs, InAs, GaP, InP,...) and III-nitride materials (GaN, InGaN, AlGaN,...). We review the way in which several innovative synthesis methods constitute the basis for the realization of highly controlled nanowires, and we combine this perspective with one of how the different families of nanowires can contribute to applications. One reason for the very intense research in this field is motivated by what they can offer to main-stream semiconductors, by which ultrahigh performing electronic (e.g., transistors) and photonic (e.g., photovoltaics, photodetectors or LEDs) technologies can be merged with silicon and CMOS. Other important aspects, also covered in the review, deals with synthesis methods that can lead to dramatic reduction of cost of fabrication and opportunities for up-scaling to mass production methods.
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Affiliation(s)
- Enrique Barrigón
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Magnus Heurlin
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden.,Sol Voltaics AB , Scheelevägen 63 , 223 63 Lund , Sweden
| | - Zhaoxia Bi
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Bo Monemar
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Lars Samuelson
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
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17
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Realization of p-type gallium nitride by magnesium ion implantation for vertical power devices. Sci Rep 2019; 9:8796. [PMID: 31217468 PMCID: PMC6584666 DOI: 10.1038/s41598-019-45177-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 05/29/2019] [Indexed: 11/30/2022] Open
Abstract
Implementing selective-area p-type doping through ion implantation is the most attractive choice for the fabrication of GaN-based bipolar power and related devices. However, the low activation efficiency of magnesium (Mg) ions and the inevitable surface decomposition during high-temperature activation annealing process still limit the use of this technology for GaN-based devices. In this work, we demonstrate successful p-type doping of GaN using protective coatings during a Mg ion implantation and thermal activation process. The p-type conduction of GaN is evidenced by the positive Seebeck coefficient obtained during thermopower characterization. On this basis, a GaN p-i-n diode is fabricated, exhibiting distinct rectifying characteristics with a turn-on voltage of 3 V with an acceptable reverse breakdown voltage of 300 V. Electron beam induced current (EBIC) and electroluminescent (EL) results further confirm the formation of p-type region due to Mg ion implantation and subsequent thermal activation. This repeatable and uniform manufacturing process can be implemented in mass production of GaN devices for versatile power and optoelectronic applications.
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18
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Korona KP, Zytkiewicz ZR, Sobanska M, Sosada FE, Dróżdż PA, Klosek K, Tchutchulashvili G. Reflectance and fast polarization dynamics of a GaN/Si nanowire ensemble. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:315301. [PMID: 29939153 DOI: 10.1088/1361-648x/aacedd] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Optical phenomena in an ensemble of high-quality GaN nanowires (NWs) grown on a Si substrate have been studied by reflectance and time-resolved luminescence. Such NWs form a structure that acts as a virtual layer that specifically reflects and polarizes light and can be characterized by an effective refractive index. In fact we have found that the NW ensembles of high NW density (high filling fraction) behave rather like a layer of effective medium described by the Maxwell Garnett approximation. Moreover, light extinction and strong depolarization are observed that we assign to scattering and interference of light inside the NW ensemble. The wavelength range of high extinction and depolarization correlates well with transverse localization wavelength estimated for such an ensemble of NWs, so we suppose that these effects are due to Anderson localization of light. We also report results of time-resolved measurements of polarization of individual emission centers including free and bound excitons (D0XA, 3.47 eV), inversion domain boundaries (IDB, 3.45 eV) and stacking faults (SF, 3.42 eV). The emission of the D0XA and SF lines is polarized perpendicular to GaN c-axis while the 3.45 eV line is polarized along the c-axis which supports a hypothesis that this line is emitted from IDBs. Time-dependent depolarization of luminescence is observed during the first 0.1 ns after excitation and is interpreted as the result of interaction of the emission centers with hot particles existing for a short time after excitation.
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Affiliation(s)
- K P Korona
- Faculty of Physics, Institute of Experimental Physics, University of Warsaw, ul. Pasteura 5, 02-923 Warsaw, Poland
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19
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Jegenyes N, Morassi M, Chrétien P, Travers L, Lu L, Julien FH, Tchernycheva M, Houzé F, Gogneau N. High Piezoelectric Conversion Properties of Axial InGaN/GaN Nanowires. NANOMATERIALS (BASEL, SWITZERLAND) 2018; 8:E367. [PMID: 29799440 PMCID: PMC6027191 DOI: 10.3390/nano8060367] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 05/18/2018] [Accepted: 05/23/2018] [Indexed: 11/21/2022]
Abstract
We demonstrate for the first time the efficient mechanical-electrical conversion properties of InGaN/GaN nanowires (NWs). Using an atomic force microscope equipped with a modified Resiscope module, we analyse the piezoelectric energy generation of GaN NWs and demonstrate an important enhancement when integrating in their volume a thick In-rich InGaN insertion. The piezoelectric response of InGaN/GaN NWs can be tuned as a function of the InGaN insertion thickness and position in the NW volume. The energy harvesting is favoured by the presence of a PtSi/GaN Schottky diode which allows to efficiently collect the piezo-charges generated by InGaN/GaN NWs. Average output voltages up to 330 ± 70 mV and a maximum value of 470 mV per NW has been measured for nanostructures integrating 70 nm-thick InGaN insertion capped with a thin GaN top layer. This latter value establishes an increase of about 35% of the piezo-conversion capacity in comparison with binary p-doped GaN NWs. Based on the measured output signals, we estimate that one layer of dense InGaN/GaN-based NW can generate a maximum output power density of about 3.3 W/cm². These results settle the new state-of-the-art for piezo-generation from GaN-based NWs and offer a promising perspective for extending the performances of the piezoelectric sources.
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Affiliation(s)
- Nikoletta Jegenyes
- Centre de Nanosciences et de Nanotechnologies-CNRS-UMR9001, Université Paris-Sud, Université Paris-Saclay, F91120 Palaiseau, France.
| | - Martina Morassi
- Centre de Nanosciences et de Nanotechnologies-CNRS-UMR9001, Université Paris-Sud, Université Paris-Saclay, F91120 Palaiseau, France.
| | - Pascal Chrétien
- Laboratoire de Génie Électrique et Électronique de Paris, UMR 8507 CNRS-Centrale-Supélec, Université Paris-Sud, Université Paris-Saclay et UPMC-Sorbonne Université, F91190 Gif-sur-Yvette, France.
| | - Laurent Travers
- Centre de Nanosciences et de Nanotechnologies-CNRS-UMR9001, Université Paris-Sud, Université Paris-Saclay, F91120 Palaiseau, France.
| | - Lu Lu
- Centre de Nanosciences et de Nanotechnologies-CNRS-UMR9001, Université Paris-Sud, Université Paris-Saclay, F91120 Palaiseau, France.
| | - Francois H Julien
- Centre de Nanosciences et de Nanotechnologies-CNRS-UMR9001, Université Paris-Sud, Université Paris-Saclay, F91120 Palaiseau, France.
| | - Maria Tchernycheva
- Centre de Nanosciences et de Nanotechnologies-CNRS-UMR9001, Université Paris-Sud, Université Paris-Saclay, F91120 Palaiseau, France.
| | - Frédéric Houzé
- Laboratoire de Génie Électrique et Électronique de Paris, UMR 8507 CNRS-Centrale-Supélec, Université Paris-Sud, Université Paris-Saclay et UPMC-Sorbonne Université, F91190 Gif-sur-Yvette, France.
| | - Noelle Gogneau
- Centre de Nanosciences et de Nanotechnologies-CNRS-UMR9001, Université Paris-Sud, Université Paris-Saclay, F91120 Palaiseau, France.
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20
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Donatini F, Pernot J. Exciton diffusion coefficient measurement in ZnO nanowires under electron beam irradiation. NANOTECHNOLOGY 2018; 29:105703. [PMID: 29313830 DOI: 10.1088/1361-6528/aaa638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In semiconductor nanowires (NWs) the exciton diffusion coefficient can be determined using a scanning electron microscope fitted with a cathodoluminescence system. High spatial and temporal resolution cathodoluminescence experiments are needed to measure independently the exciton diffusion length and lifetime in single NWs. However, both diffusion length and lifetime can be affected by the electron beam bombardment during observation and measurement. Thus, in this work the exciton lifetime in a ZnO NW is measured versus the electron beam dose (EBD) via a time-resolved cathodoluminescence experiment with a temporal resolution of 50 ps. The behavior of the measured exciton lifetime is consistent with our recent work on the EBD dependence of the exciton diffusion length in similar NWs investigated under comparable SEM conditions. Combining the two results, the exciton diffusion coefficient in ZnO is determined at room temperature and is found constant over the full span of EBD.
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Affiliation(s)
- Fabrice Donatini
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut NEEL, F-38000 Grenoble, France
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21
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Fang Z, Donatini F, Daudin B, Pernot J. Axial p-n junction and space charge limited current in single GaN nanowire. NANOTECHNOLOGY 2018; 29:01LT01. [PMID: 29130887 DOI: 10.1088/1361-6528/aa9a0e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The electrical characterizations of individual basic GaN nanostructures, such as axial nanowire (NW) p-n junctions, are becoming indispensable and crucial for the fully controlled realization of GaN NW based devices. In this study, electron beam induced current (EBIC) measurements were performed on two single axial GaN p-n junction NWs grown by plasma-assisted molecular beam epitaxy. I-V characteristics revealed that both ohmic and space charge limited current (SCLC) regimes occur in GaN p-n junction NW. Thanks to an improved contact process, both the electric field induced by the p-n junction and the SCLC in the p-part of GaN NW were disclosed and delineated by EBIC signals under different biases. Analyzing the EBIC profiles in the vicinity of the p-n junction under 0 V and reverse bias, we deduced a depletion width in the range of 116-125 nm. Following our previous work, the acceptor N a doping level was estimated to be 2-3 × 1017 at cm-3 assuming a donor level N d of 2-3 × 1018 at cm-3. The hole diffusion length in n-GaN was determined to be 75 nm for NW #1 and 43 nm for NW #2, demonstrating a low surface recombination velocity at the m-plane facet of n-GaN NW. Under forward bias, EBIC imaging visualized the electric field induced by the SCLC close to p-side contact, in agreement with unusual SCLC previously reported in GaN NWs.
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Affiliation(s)
- Zhihua Fang
- Univ. Grenoble Alpes, F-38000 Grenoble, France. CEA, INAC-PHELIQS, 'Nanophysique et semiconducteurs' group, F-38000 Grenoble, France. CNRS, Inst. NEEL, F-38042 Grenoble, France
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22
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Brubaker MD, Genter KL, Weber JC, Spann BT, Roshko A, Blanchard PT, Harvey TE, Bertness KA. Core-shell p-i-n GaN nanowire LEDs by N-polar selective area growth. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2018; 10725. [PMID: 33343056 DOI: 10.1117/12.2322832] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
GaN nanowire LEDs with radial p-i-n junctions were grown by molecular beam epitaxy using N-polar selective area growth on Si(111) substrates. The N-polar selective area growth process facilitated the growth of isolated and high-aspect-ratio n-type NW cores that were not subject to self-shadowing effects during the subsequent growth of a conformal low-temperature Mg:GaN shell. LED devices were fabricated from single-NW and multiple-NW arrays in their as-grown configuration by contacting the n-type core through an underlying conductive GaN layer and the p-type NW shell via a metallization layer. The NW LEDs exhibited rectifying I-V characteristics with a sharp turn-on voltage near the GaN bandgap and low reverse bias leakage current. Under forward bias, the NW LEDs produced electroluminescence with a peak emission wavelength near 380 nm and exhibited a small spectral blueshift with increasing current injection, both of which are consistent with electron recombination in the p-type shell layer through donor-acceptor-pair recombination. These core-shell NW devices demonstrate N-polar selective area growth as an effective technique for producing on-chip nanoscale light sources.
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Affiliation(s)
- Matt D Brubaker
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, USA 80305
| | - Kristen L Genter
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, USA 80305.,Department of Mechanical Engineering, University of Colorado, 1111 Engineering Drive, Boulder, CO USA 80309
| | - Joel C Weber
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, USA 80305
| | - Bryan T Spann
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, USA 80305
| | - Alexana Roshko
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, USA 80305
| | - Paul T Blanchard
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, USA 80305
| | - Todd E Harvey
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, USA 80305
| | - Kris A Bertness
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, USA 80305
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Durand C, Carlin JF, Bougerol C, Gayral B, Salomon D, Barnes JP, Eymery J, Butté R, Grandjean N. Thin-Wall GaN/InAlN Multiple Quantum Well Tubes. NANO LETTERS 2017; 17:3347-3355. [PMID: 28441498 DOI: 10.1021/acs.nanolett.6b04852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Thin-wall tubes composed of nitride semiconductors (III-N compounds) based on GaN/InAlN multiple quantum wells (MQWs) are fabricated by metal-organic vapor-phase epitaxy in a simple and full III-N approach. The synthesis of such MQW-tubes is based on the growth of N-polar c-axis vertical GaN wires surrounded by a core-shell MQW heterostructure followed by in situ selective etching using controlled H2/NH3 annealing at 1010 °C to remove the inner GaN wire part. After this process, well-defined MQW-based tubes having nonpolar m-plane orientation exhibit UV light near 330 nm up to room temperature, consistent with the emission of GaN/InAlN MQWs. Partially etched tubes reveal a quantum-dotlike signature originating from nanosized GaN residuals present inside the tubes. The possibility to fabricate in a simple way thin-wall III-N tubes composed of an embedded MQW-based active region offering controllable optical emission properties constitutes an important step forward to develop new nitride devices such as emitters, detectors or sensors based on tubelike nanostructures.
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Affiliation(s)
- Christophe Durand
- Université Grenoble Alpes , 38000 Grenoble, France
- Nanophysique et Semiconducteurs Group, CEA, INAC-PHELIQS , 17 Avenue des Martyrs, 38000 Grenoble, France
| | - Jean-François Carlin
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
| | - Catherine Bougerol
- Université Grenoble Alpes , 38000 Grenoble, France
- Nanophysique et Semiconducteurs Group, CNRS, Institut Néel , 25 Avenue des Martyrs, 38000 Grenoble, France
| | - Bruno Gayral
- Université Grenoble Alpes , 38000 Grenoble, France
- Nanophysique et Semiconducteurs Group, CEA, INAC-PHELIQS , 17 Avenue des Martyrs, 38000 Grenoble, France
| | - Damien Salomon
- European Synchrotron Radiation Facility , 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Jean-Paul Barnes
- Université Grenoble Alpes , 38000 Grenoble, France
- CEA, LETI , MINATEC Campus, 38000 Grenoble France
| | - Joël Eymery
- Université Grenoble Alpes , 38000 Grenoble, France
- Nanophysique et Semiconducteurs Group, CEA, INAC-PHELIQS , 17 Avenue des Martyrs, 38000 Grenoble, France
| | - Raphaël Butté
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
| | - Nicolas Grandjean
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
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Jamond N, Chrétien P, Gatilova L, Galopin E, Travers L, Harmand JC, Glas F, Houzé F, Gogneau N. Energy harvesting efficiency in GaN nanowire-based nanogenerators: the critical influence of the Schottky nanocontact. NANOSCALE 2017; 9:4610-4619. [PMID: 28323294 DOI: 10.1039/c7nr00647k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The performances of 1D-nanostructure based nanogenerators are governed by the ability of nanostructures to efficiently convert mechanical deformation into electrical energy, and by the efficiency with which this piezo-generated energy is harvested. In this paper, we highlight the crucial influence of the GaN nanowire-metal Schottky nanocontact on the energy harvesting efficiency. Three different metals, p-type doped diamond, PtSi and Pt/Ir, have been investigated. By using an atomic force microscope equipped with a Resiscope module, we demonstrate that the harvesting of piezo-generated energy is up to 2.4 times more efficient using a platinum-based Schottky nanocontact compared to a doped diamond-based nanocontact. In light of Schottky contact characteristics, we evidence that the conventional description of the Schottky diode cannot be applied. The contact is governed by its nanometer size. This specific behaviour induces notably a lowering of the Schottky barrier height, which gives rise to an enhanced conduction. We especially demonstrate that this effective thinning is directly correlated with the improvement of the energy harvesting efficiency, which is much pronounced for Pt-based Schottky diodes. These results constitute a building block to the overall improvement of NW-based nanogenerator devices.
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Affiliation(s)
- Nicolas Jamond
- Centre des Nanosciences et des Nanotechnologies, site-Marcoussis, Université Paris-Saclay, CNRS-C2N-UMR9001, Route de Nozay, 91460 Marcoussis, France.
| | - Pascal Chrétien
- Laboratoire de Génie Electrique de Paris, UMR CNRS-Supélec 8507, Universités Pierre et Marie Curie et Paris-Sud, 11 rue Joliot-Curie, 91192 Gif Sur Yvette, France
| | - Lina Gatilova
- Observatoire de Paris, LERMA, UMR 8112, avenue de l'Observatoire, 75014 Paris, France
| | - Elisabeth Galopin
- Centre des Nanosciences et des Nanotechnologies, site-Marcoussis, Université Paris-Saclay, CNRS-C2N-UMR9001, Route de Nozay, 91460 Marcoussis, France.
| | - Laurent Travers
- Centre des Nanosciences et des Nanotechnologies, site-Marcoussis, Université Paris-Saclay, CNRS-C2N-UMR9001, Route de Nozay, 91460 Marcoussis, France.
| | - Jean-Christophe Harmand
- Centre des Nanosciences et des Nanotechnologies, site-Marcoussis, Université Paris-Saclay, CNRS-C2N-UMR9001, Route de Nozay, 91460 Marcoussis, France.
| | - Frank Glas
- Centre des Nanosciences et des Nanotechnologies, site-Marcoussis, Université Paris-Saclay, CNRS-C2N-UMR9001, Route de Nozay, 91460 Marcoussis, France.
| | - Frédéric Houzé
- Laboratoire de Génie Electrique de Paris, UMR CNRS-Supélec 8507, Universités Pierre et Marie Curie et Paris-Sud, 11 rue Joliot-Curie, 91192 Gif Sur Yvette, France
| | - Noëlle Gogneau
- Centre des Nanosciences et des Nanotechnologies, site-Marcoussis, Université Paris-Saclay, CNRS-C2N-UMR9001, Route de Nozay, 91460 Marcoussis, France.
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Zhang H, Dai X, Guan N, Messanvi A, Neplokh V, Piazza V, Vallo M, Bougerol C, Julien FH, Babichev A, Cavassilas N, Bescond M, Michelini F, Foldyna M, Gautier E, Durand C, Eymery J, Tchernycheva M. Flexible Photodiodes Based on Nitride Core/Shell p-n Junction Nanowires. ACS APPLIED MATERIALS & INTERFACES 2016; 8:26198-26206. [PMID: 27615556 PMCID: PMC5054459 DOI: 10.1021/acsami.6b06414] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 09/12/2016] [Indexed: 05/27/2023]
Abstract
A flexible nitride p-n photodiode is demonstrated. The device consists of a composite nanowire/polymer membrane transferred onto a flexible substrate. The active element for light sensing is a vertical array of core/shell p-n junction nanowires containing InGaN/GaN quantum wells grown by MOVPE. Electron/hole generation and transport in core/shell nanowires are modeled within nonequilibrium Green function formalism showing a good agreement with experimental results. Fully flexible transparent contacts based on a silver nanowire network are used for device fabrication, which allows bending the detector to a few millimeter curvature radius without damage. The detector shows a photoresponse at wavelengths shorter than 430 nm with a peak responsivity of 0.096 A/W at 370 nm under zero bias. The operation speed for a 0.3 × 0.3 cm2 detector patch was tested between 4 Hz and 2 kHz. The -3 dB cutoff was found to be ∼35 Hz, which is faster than the operation speed for typical photoconductive detectors and which is compatible with UV monitoring applications.
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Affiliation(s)
- Hezhi Zhang
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
| | - Xing Dai
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
| | - Nan Guan
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
| | - Agnes Messanvi
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
- Université
Grenoble Alpes, Grenoble 38000, France
- “Nanophysique
et Semiconducteurs” group, CEA, INAC-SP2M, 17 rue des Martyrs, Grenoble 38000, France
| | - Vladimir Neplokh
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
| | - Valerio Piazza
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
| | - Martin Vallo
- “Nanophysique
et Semiconducteurs” group, CEA, INAC-SP2M, 17 rue des Martyrs, Grenoble 38000, France
| | - Catherine Bougerol
- Université
Grenoble Alpes, Grenoble 38000, France
- “Nanophysique
et Semiconducteurs” group, CEA, INAC-SP2M, 17 rue des Martyrs, Grenoble 38000, France
| | - François H. Julien
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
| | - Andrey Babichev
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
- ITMO
University, St. Petersburg 197101, Russia
| | - Nicolas Cavassilas
- Aix Marseille
Université, CNRS, Université
de Toulon, IM2NP UMR
7334, 13397 Marseille, France
| | - Marc Bescond
- Aix Marseille
Université, CNRS, Université
de Toulon, IM2NP UMR
7334, 13397 Marseille, France
| | - Fabienne Michelini
- Aix Marseille
Université, CNRS, Université
de Toulon, IM2NP UMR
7334, 13397 Marseille, France
| | - Martin Foldyna
- LPICM-CNRS,
Laboratoire de Physique des Interfaces et Couches Minces, Ecole Polytechnique, Palaiseau 91128, France
| | - Eric Gautier
- Université
Grenoble Alpes, Grenoble 38000, France
- CEA,
INAC-SPINTEC, 38000 Grenoble, France
| | - Christophe Durand
- Université
Grenoble Alpes, Grenoble 38000, France
- “Nanophysique
et Semiconducteurs” group, CEA, INAC-SP2M, 17 rue des Martyrs, Grenoble 38000, France
| | - Joël Eymery
- “Nanophysique
et Semiconducteurs” group, CEA, INAC-SP2M, 17 rue des Martyrs, Grenoble 38000, France
| | - Maria Tchernycheva
- Centre
de Nanosciences et de Nanotechnologies, UMR9001 CNRS, University Paris Sud, University Paris Saclay, Orsay 91405, France
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26
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Minj A, Cros A, Auzelle T, Pernot J, Daudin B. Direct assessment of p-n junctions in single GaN nanowires by Kelvin probe force microscopy. NANOTECHNOLOGY 2016; 27:385202. [PMID: 27518150 DOI: 10.1088/0957-4484/27/38/385202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Making use of Kelvin probe force microscopy, in dark and under ultraviolet illumination, we study the characteristics of p-n junctions formed along the axis of self-organized GaN nanowires (NWs). We map the contact potential difference of the single NW p-n junctions to locate the space charge region and directly measure the depletion width and the junction voltage. Simulations indicate a shrinkage of the built-in potential for NWs with small diameter due to surface band bending, in qualitative agreement with the measurements. The photovoltage of the NW/substrate contact is studied by analyzing the response of NW segments with p- and n-type doping under illumination. Our results show that the shifts of the Fermi levels, and not the changes in surface band bending, are the most important effects under above band-gap illumination. The quantitative electrical information obtained here is important for the use of NW p-n junctions as photovoltaic or rectifying devices at the nanoscale, and is especially relevant since the technique does not require the formation of ohmic contacts to the NW junction.
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Affiliation(s)
- Albert Minj
- Institute of Materials Science (ICMUV), Universidad de Valencia, PO Box 22085, E-46071, Valencia, Spain. CIMAP, UMR 6252, ENSICAEN, 6 Bd Maréchal Juin, F-14050 Caen Cedex 4, France
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27
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Location and Visualization of Working p-n and/or n-p Junctions by XPS. Sci Rep 2016; 6:32482. [PMID: 27582318 PMCID: PMC5007498 DOI: 10.1038/srep32482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/08/2016] [Indexed: 01/09/2023] Open
Abstract
X-ray photoelectron spectroscopy (XPS) is used to follow some of the electrical properties of a segmented silicon photodetector, fabricated in a p-n-p configuration, during operation under various biasing configurations. Mapping of the binding energy position of Si2p reveals the shift in the position of the junctions with respect to the polarity of the DC bias applied. Use of squared and triangular shaped wave excitations, while recording XPS data, allows tapping different electrical properties of the device under normal operational conditions, as well as after exposing parts of it to harsh physical and chemical treatments. Unique and chemically specific electrical information can be gained with this noninvasive approach which can be useful especially for localized device characterization and failure analyses.
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28
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Kumar A, Heilmann M, Latzel M, Kapoor R, Sharma I, Göbelt M, Christiansen SH, Kumar V, Singh R. Barrier inhomogeneities limited current and 1/f noise transport in GaN based nanoscale Schottky barrier diodes. Sci Rep 2016; 6:27553. [PMID: 27282258 PMCID: PMC4901317 DOI: 10.1038/srep27553] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/20/2016] [Indexed: 12/21/2022] Open
Abstract
The electrical behaviour of Schottky barrier diodes realized on vertically standing individual GaN nanorods and array of nanorods is investigated. The Schottky diodes on individual nanorod show highest barrier height in comparison with large area diodes on nanorods array and epitaxial film which is in contrast with previously published work. The discrepancy between the electrical behaviour of nanoscale Schottky diodes and large area diodes is explained using cathodoluminescence measurements, surface potential analysis using Kelvin probe force microscopy and 1ow frequency noise measurements. The noise measurements on large area diodes on nanorods array and epitaxial film suggest the presence of barrier inhomogeneities at the metal/semiconductor interface which deviate the noise spectra from Lorentzian to 1/f type. These barrier inhomogeneities in large area diodes resulted in reduced barrier height whereas due to the limited role of barrier inhomogeneities in individual nanorod based Schottky diode, a higher barrier height is obtained.
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Affiliation(s)
- Ashutosh Kumar
- Department of Physics, Indian Institute of Technology Delhi, New Delhi-110016, India
- Nanoscale Research Facility, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - M. Heilmann
- Max Planck Institute for the Science of Light, Günther-Scharowsky-Straße 1/Bau 24, 91058 Erlangen, Germany
| | - Michael Latzel
- Max Planck Institute for the Science of Light, Günther-Scharowsky-Straße 1/Bau 24, 91058 Erlangen, Germany
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Institute of Optics, Information and Photonics, Staudtstr. 7/B2, 91058 Erlangen, Germany
| | - Raman Kapoor
- Nanoscale Research Facility, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Intu Sharma
- Department of Physics, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - M. Göbelt
- Max Planck Institute for the Science of Light, Günther-Scharowsky-Straße 1/Bau 24, 91058 Erlangen, Germany
| | - Silke H. Christiansen
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Institute of Optics, Information and Photonics, Staudtstr. 7/B2, 91058 Erlangen, Germany
- Institute of Nano-Architectures for Energy Conversion, Helmholtz - Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - Vikram Kumar
- Department of Physics, Indian Institute of Technology Delhi, New Delhi-110016, India
- Nanoscale Research Facility, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Rajendra Singh
- Department of Physics, Indian Institute of Technology Delhi, New Delhi-110016, India
- Nanoscale Research Facility, Indian Institute of Technology Delhi, New Delhi-110016, India
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29
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Donatini F, de Luna Bugallo A, Tchoulfian P, Chicot G, Sartel C, Sallet V, Pernot J. Comparison of Three E-Beam Techniques for Electric Field Imaging and Carrier Diffusion Length Measurement on the Same Nanowires. NANO LETTERS 2016; 16:2938-2944. [PMID: 27105083 DOI: 10.1021/acs.nanolett.5b04710] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Whereas nanowire (NW)-based devices offer numerous advantages compared to bulk ones, their performances are frequently limited by an incomplete understanding of their properties where surface effect should be carefully considered. Here, we demonstrate the ability to spatially map the electric field and determine the exciton diffusion length in NW by using an electron beam as the single excitation source. This approach is performed on numerous single ZnO NW Schottky diodes whose NW radius vary from 42.5 to 175 nm. The dominant impact of the surface on the NW properties is revealed through the comparison of three different physical quantities recorded on the same NW: electron-beam induced current, cathodoluminescence, and secondary electron signal. Indeed, the space charge region near the Schottky contact exhibits an unusual linear variation with reverse bias whatever the NW radius. On the contrary, the exciton diffusion length is shown to be controlled by the NW radius through surface recombination. This systematic comparison performed on a single ZnO NW demonstrates the power of these complementary techniques in understanding NW properties.
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Affiliation(s)
- F Donatini
- Université Grenoble Alpes , F-38000 Grenoble, France
- CNRS, Institut NEEL , F-38042 Grenoble, France
| | - Andres de Luna Bugallo
- Université Grenoble Alpes , F-38000 Grenoble, France
- CNRS, Institut NEEL , F-38042 Grenoble, France
| | - Pierre Tchoulfian
- Université Grenoble Alpes , F-38000 Grenoble, France
- CNRS, Institut NEEL , F-38042 Grenoble, France
- CEA, LETI , Minatec Campus, F-38054 Grenoble, France
| | - Gauthier Chicot
- Université Grenoble Alpes , F-38000 Grenoble, France
- CNRS, Institut NEEL , F-38042 Grenoble, France
| | - Corinne Sartel
- Groupe d'Etude de la Matière Condensée (GEMAC), CNRS Université de Versailles St. Quentin, Université Paris-Saclay , 78035 Versailles Cedex, France
| | - Vincent Sallet
- Groupe d'Etude de la Matière Condensée (GEMAC), CNRS Université de Versailles St. Quentin, Université Paris-Saclay , 78035 Versailles Cedex, France
| | - Julien Pernot
- Université Grenoble Alpes , F-38000 Grenoble, France
- CNRS, Institut NEEL , F-38042 Grenoble, France
- Institut Universitaire de France , 103 Boulevard Saint-Michel, F-75005 Paris, France
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30
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A low cost, green method to synthesize GaN nanowires. Sci Rep 2015; 5:17692. [PMID: 26643613 PMCID: PMC4672344 DOI: 10.1038/srep17692] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 11/04/2015] [Indexed: 11/09/2022] Open
Abstract
The synthesis of gallium nitride nanowires (GaN NWs) by plasma enhanced chemical vapor deposition (PECVD) are successfully demonstrated in this work. The simple and green synthesis route is to introduce gallium oxide (Ga2O3) and nitrogen (N2) for the growth of nanowires. The prepared GaN nanowires have a single crystalline wurtzite structure, which the length of some nanowires is up to 20 μm, with a maximum diameter about 140 nm. The morphology and quantity of the nanowires can be modulated by the growth substrate and process parameters. In addition, the photoluminescence and field emission properties of the prepared GaN nanowires have been investigated, which were found to be largely affected by their structures. This work renders an environmentally benign strategy and a facile approach for controllable structures on nanodevice.
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31
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Dai X, Messanvi A, Zhang H, Durand C, Eymery J, Bougerol C, Julien FH, Tchernycheva M. Flexible Light-Emitting Diodes Based on Vertical Nitride Nanowires. NANO LETTERS 2015; 15:6958-64. [PMID: 26322549 DOI: 10.1021/acs.nanolett.5b02900] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate large area fully flexible blue LEDs based on core/shell InGaN/GaN nanowires grown by MOCVD. The fabrication relies on polymer encapsulation, nanowire lift-off and contacting using silver nanowire transparent electrodes. The LEDs exhibit rectifying behavior with a light-up voltage around 3 V. The devices show no electroluminescence degradation neither under multiple bending down to 3 mm curvature radius nor in time for more than one month storage in ambient conditions without any protecting encapsulation. Fully transparent flexible LEDs with high optical transmittance are also fabricated. Finally, a two-color flexible LED emitting in the green and blue spectral ranges is demonstrated combining two layers of InGaN/GaN nanowires with different In contents.
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Affiliation(s)
- Xing Dai
- Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud XI , 91405 Orsay, France
| | - Agnes Messanvi
- Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud XI , 91405 Orsay, France
- Université Grenoble Alpes , 38000 Grenoble, France
- "Nanophysique et Semiconducteurs" group, CEA, INAC-SP2M , 17 Avenue des Martyrs, 38000 Grenoble, France
| | - Hezhi Zhang
- Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud XI , 91405 Orsay, France
| | - Christophe Durand
- Université Grenoble Alpes , 38000 Grenoble, France
- "Nanophysique et Semiconducteurs" group, CEA, INAC-SP2M , 17 Avenue des Martyrs, 38000 Grenoble, France
| | - Joël Eymery
- Université Grenoble Alpes , 38000 Grenoble, France
- "Nanophysique et Semiconducteurs" group, CEA, INAC-SP2M , 17 Avenue des Martyrs, 38000 Grenoble, France
| | - Catherine Bougerol
- Université Grenoble Alpes , 38000 Grenoble, France
- "Nanophysique et Semiconducteurs" group, CNRS, Institut Néel , 25 Avenue des Martyrs, 38000 Grenoble, France
| | - François H Julien
- Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud XI , 91405 Orsay, France
| | - Maria Tchernycheva
- Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud XI , 91405 Orsay, France
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32
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Chemical Visualization of a GaN p-n junction by XPS. Sci Rep 2015; 5:14091. [PMID: 26359762 PMCID: PMC4566124 DOI: 10.1038/srep14091] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 08/17/2015] [Indexed: 12/30/2022] Open
Abstract
We report on an operando XPS investigation of a GaN diode, by recording the Ga2p3/2 peak position under both forward and reverse bias. Areal maps of the peak positions under reverse bias are completely decoupled with respect to doped regions and allow a novel chemical visualization of the p-n junction in a 2-D fashion. Other electrical properties of the device, such as leakage current, resistivity of the domains are also tapped via recording line-scan spectra. Application of a triangular voltage excitation enables probing photoresponse of the device.
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33
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Tchernycheva M, Neplokh V, Zhang H, Lavenus P, Rigutti L, Bayle F, Julien FH, Babichev A, Jacopin G, Largeau L, Ciechonski R, Vescovi G, Kryliouk O. Core-shell InGaN/GaN nanowire light emitting diodes analyzed by electron beam induced current microscopy and cathodoluminescence mapping. NANOSCALE 2015; 7:11692-11701. [PMID: 26100114 DOI: 10.1039/c5nr00623f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report on the electron beam induced current (EBIC) microscopy and cathodoluminescence (CL) characterization correlated with compositional analysis of light emitting diodes based on core/shell InGaN/GaN nanowire arrays. The EBIC mapping of cleaved fully operational devices allows to probe the electrical properties of the active region with a nanoscale resolution. In particular, the electrical activity of the p-n junction on the m-planes and on the semi-polar planes of individual nanowires is assessed in top view and cross-sectional geometries. The EBIC maps combined with CL characterization demonstrate the impact of the compositional gradients along the wire axis on the electrical and optical signals: the reduction of the EBIC signal toward the nanowire top is accompanied by an increase of the CL intensity. This effect is interpreted as a consequence of the In and Al gradients in the quantum well and in the electron blocking layer, which influence the carrier extraction efficiency. The interface between the nanowire core and the radially grown layer is shown to produce in some cases a transitory EBIC signal. This observation is explained by the presence of charged traps at this interface, which can be saturated by electron irradiation.
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Affiliation(s)
- M Tchernycheva
- Institut d'Electronique Fondamentale, UMR 8622 CNRS, University Paris Sud, 91405 Orsay cedex, France.
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34
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Renault O, Morin J, Tchoulfian P, Chevalier N, Feyer V, Pernot J, Schneider CM. Spectroscopic XPEEM of highly conductive SI-doped GaN wires. Ultramicroscopy 2015; 159 Pt 3:476-81. [PMID: 26004038 DOI: 10.1016/j.ultramic.2015.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 04/20/2015] [Accepted: 05/06/2015] [Indexed: 11/26/2022]
Abstract
Using soft X-ray photoelectron emission microscopy (XPEEM), complemented by scanning Auger microscopy (SAM) and scanning capacitance microscopy, we have quantitatively studied the incorporation of silicon and band bending at the surface (m-facet) of an individual, highly conductive Si-doped GaN micro-wires (Tchoulfian et al., Applied Physics Letters 102 (12), 2013). Electrically active n-dopants Si atoms in Ga interstitial sites are detected as nitride bonding states in the high-resolution Si2p core level spectra, and represent only a small fraction (<10%) of the overall Si surface concentration measured by SAM. The derived carrier concentration of 2×10(21) at cm(-3) is in reasonable agreement with electrical measurements. A consistent surface band bending of ~1 eV is directly evidenced by surface photo-voltage measurements. Such an approach combining different surface-sensitive microscopies is of interest for studying other heavily doped semiconducting wires.
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Affiliation(s)
- O Renault
- Univ. Grenoble Alpes, F-38000 Grenoble, France; CEA, LETI, MINATEC Campus, F-38054 Grenoble, France.
| | - J Morin
- Univ. Grenoble Alpes, F-38000 Grenoble, France; CEA, LETI, MINATEC Campus, F-38054 Grenoble, France
| | - P Tchoulfian
- Univ. Grenoble Alpes, F-38000 Grenoble, France; CEA, LETI, MINATEC Campus, F-38054 Grenoble, France; CNRS, Inst. NEEL, F-38042 Grenoble, France
| | - N Chevalier
- Univ. Grenoble Alpes, F-38000 Grenoble, France; CEA, LETI, MINATEC Campus, F-38054 Grenoble, France
| | - V Feyer
- Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich, Germany
| | - J Pernot
- Univ. Grenoble Alpes, F-38000 Grenoble, France; CNRS, Inst. NEEL, F-38042 Grenoble, France; Institut Universitaire de France, F-75005 Paris, France
| | - C M Schneider
- Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich, Germany
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