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Laukkanen P, Punkkinen M, Kuzmin M, Kokko K, Liu X, Radfar B, Vähänissi V, Savin H, Tukiainen A, Hakkarainen T, Viheriälä J, Guina M. Bridging the gap between surface physics and photonics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:044501. [PMID: 38373354 DOI: 10.1088/1361-6633/ad2ac9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 02/19/2024] [Indexed: 02/21/2024]
Abstract
Use and performance criteria of photonic devices increase in various application areas such as information and communication, lighting, and photovoltaics. In many current and future photonic devices, surfaces of a semiconductor crystal are a weak part causing significant photo-electric losses and malfunctions in applications. These surface challenges, many of which arise from material defects at semiconductor surfaces, include signal attenuation in waveguides, light absorption in light emitting diodes, non-radiative recombination of carriers in solar cells, leakage (dark) current of photodiodes, and light reflection at solar cell interfaces for instance. To reduce harmful surface effects, the optical and electrical passivation of devices has been developed for several decades, especially with the methods of semiconductor technology. Because atomic scale control and knowledge of surface-related phenomena have become relevant to increase the performance of different devices, it might be useful to enhance the bridging of surface physics to photonics. Toward that target, we review some evolving research subjects with open questions and possible solutions, which hopefully provide example connecting points between photonic device passivation and surface physics. One question is related to the properties of the wet chemically cleaned semiconductor surfaces which are typically utilized in device manufacturing processes, but which appear to be different from crystalline surfaces studied in ultrahigh vacuum by physicists. In devices, a defective semiconductor surface often lies at an embedded interface formed by a thin metal or insulator film grown on the semiconductor crystal, which makes the measurements of its atomic and electronic structures difficult. To understand these interface properties, it is essential to combine quantum mechanical simulation methods. This review also covers metal-semiconductor interfaces which are included in most photonic devices to transmit electric carriers to the semiconductor structure. Low-resistive and passivated contacts with an ultrathin tunneling barrier are an emergent solution to control electrical losses in photonic devices.
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Affiliation(s)
- Pekka Laukkanen
- Department of Physics and Astronomy, University of Turku, Turku, Finland
| | - Marko Punkkinen
- Department of Physics and Astronomy, University of Turku, Turku, Finland
| | - Mikhail Kuzmin
- Department of Physics and Astronomy, University of Turku, Turku, Finland
| | - Kalevi Kokko
- Department of Physics and Astronomy, University of Turku, Turku, Finland
| | - Xiaolong Liu
- Department of Electronics and Nanoengineering, Aalto University, Espoo, Finland
| | - Behrad Radfar
- Department of Electronics and Nanoengineering, Aalto University, Espoo, Finland
| | - Ville Vähänissi
- Department of Electronics and Nanoengineering, Aalto University, Espoo, Finland
| | - Hele Savin
- Department of Electronics and Nanoengineering, Aalto University, Espoo, Finland
| | - Antti Tukiainen
- Optoelectronics Research Centre, Tampere University, Tampere, Finland
| | - Teemu Hakkarainen
- Optoelectronics Research Centre, Tampere University, Tampere, Finland
| | - Jukka Viheriälä
- Optoelectronics Research Centre, Tampere University, Tampere, Finland
| | - Mircea Guina
- Optoelectronics Research Centre, Tampere University, Tampere, Finland
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2
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Shugurov KY, Mozharov AM, Fedorov VV, Blokhin SA, Neplokh VV, Mukhin IS. Extremely high frequency Schottky diodes based on single GaN nanowires. NANOTECHNOLOGY 2023; 34:245204. [PMID: 36928235 DOI: 10.1088/1361-6528/acc4cb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Gallium nitride (GaN) is one of the most promising materials for high-frequency devices owing to its prominent material properties. We report on the fabrication and study of a series of Schottky diodes in the ground-signal-ground topology based on individual GaN nanowires. The electrical characterization ofI-Vcurves demonstrated relatively high ideality factor value (about 6-9) in comparison to the planar Au/GaN diodes that can be attributed to the nanowire geometry. The effective barrier height in the studied structures was defined in the range of 0.25-0.4 eV. The small-signal frequency analysis was employed to study the dependency of the scattering parameters in the broad range from 0.1 to 40 GHz. The approximation fitting of the experimental data indicated the record high cutoff frequency of about 165.8 GHz.
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Affiliation(s)
| | | | - V V Fedorov
- Alferov University, Saint-Petersburg, Russia
| | | | - V V Neplokh
- Alferov University, Saint-Petersburg, Russia
- Peter the Great St.Petersburg Polytechnic University, Saint-Petersburg, Russia
- St. Petersburg State University, Saint-Petersburg, Russia
| | - I S Mukhin
- Alferov University, Saint-Petersburg, Russia
- Peter the Great St.Petersburg Polytechnic University, Saint-Petersburg, Russia
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3
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Lin F, Cui J, Zhang Z, Wei Z, Hou X, Meng B, Liu Y, Tang J, Li K, Liao L, Hao Q. GaAs Nanowire Photodetectors Based on Au Nanoparticles Modification. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1735. [PMID: 36837365 PMCID: PMC9967453 DOI: 10.3390/ma16041735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
A high-performance GaAs nanowire photodetector was fabricated based on the modification of Au nanoparticles (NPs). Au nanoparticles prepared by thermal evaporation were used to modify the defects on the surface of GaAs nanowires. Plasmons and Schottky barriers were also introduced on the surface of the GaAs nanowires, to enhance their light absorption and promote the separation of carriers inside the GaAs nanowires. The research results show that under the appropriate modification time, the dark current of GaAs nanowire photodetectors was reduced. In addition, photocurrent photodetectors increased from 2.39 × 10-10 A to 1.26 × 10-9 A. The responsivity of GaAs nanowire photodetectors correspondingly increased from 0.569 A∙W-1 to 3.047 A∙W-1. The reasons for the improvement of the photodetectors' performance after modification were analyzed through the energy band theory model. This work proposes a new method to improve the performance of GaAs nanowire photodetectors.
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Affiliation(s)
- Fengyuan Lin
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
| | - Jinzhi Cui
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
| | - Zhihong Zhang
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
| | - Zhipeng Wei
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
| | - Xiaobing Hou
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
| | - Bingheng Meng
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
| | - Yanjun Liu
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jilong Tang
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
| | - Kexue Li
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
| | - Lei Liao
- State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Semiconductors (College of Integrated Circuits), Hunan University, Changsha 410082, China
| | - Qun Hao
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
- School of Optoelectronics, Beijing Institute of Technology, Beijing 100081, China
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4
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Jacob B, Camarneiro F, Borme J, Bondarchuk O, Nieder JB, Romeira B. Surface Passivation of III-V GaAs Nanopillars by Low-Frequency Plasma Deposition of Silicon Nitride for Active Nanophotonic Devices. ACS APPLIED ELECTRONIC MATERIALS 2022; 4:3399-3410. [PMID: 36570334 PMCID: PMC9778088 DOI: 10.1021/acsaelm.2c00195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Numerous efforts have been devoted to improve the electronic and optical properties of III-V compound materials via reduction of their nonradiative states, aiming at highly efficient III-V sub-micrometer active devices and circuits. Despite many advances, the poor reproducibility and short-term passivation effect of chemical treatments, such as sulfidation and nitridation, requires the use of protective encapsulation methods, not only to protect the surface, but also to provide electrical isolation for device manufacturing. There is still a controversial debate on which combination of chemical treatment and capping dielectric layer can best reproducibly protect the crystal surface of III-V materials while being compatible with readily available semiconductor-foundry plasma deposition methods. This work reports on a systematic experimental study on the role of sulfide ammonium chemical treatment followed by dielectric coating (either silicon oxide or nitride) in the passivation effect of GaAs/AlGaAs nanopillars. Our results conclusively show that, under ambient conditions, the best surface passivation is achieved using ammonium sulfide followed by encapsulation with a thin layer of silicon nitride by low-frequency plasma-enhanced chemical deposition. Here, the sulfurized GaAs surfaces, high level of hydrogen ions, and low-frequency (380 kHz) excitation plasma that enable intense bombardment of hydrogen, all seem to provide a combined active role in the passivation mechanism of the pillars by reducing the surface states. As a result, we observe up to a 29-fold increase of the photoluminescence (PL) integrated intensity for the best samples as compared to untreated nanopillars. X-ray photoelectron spectroscopy analysis confirms the best treatments show remarkable removal of gallium and arsenic native oxides. Time-resolved micro-PL measurements display nanosecond lifetimes resulting in a record-low surface recombination velocity of ∼1.1 × 104 cm s-1 for dry-etched GaAs nanopillars. We achieve robust, stable, and long-term passivated nanopillar surfaces, which creates expectations for remarkable high internal quantum efficiency (IQE > 0.5) in nanoscale light-emitting diodes. The enhanced performance paves the way to many other nanostructures and devices such as miniature resonators, lasers, photodetectors, and solar cells, opening remarkable prospects for GaAs active nanophotonic devices.
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Affiliation(s)
- Bejoys Jacob
- INL
− International Iberian Nanotechnology Laboratory, Ultrafast
Bio- and Nanophotonics group, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal
| | - Filipe Camarneiro
- INL
− International Iberian Nanotechnology Laboratory, Ultrafast
Bio- and Nanophotonics group, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal
| | - Jérôme Borme
- INL
− International Iberian Nanotechnology Laboratory, 2D Materials
and Devices group, Av.
Mestre José Veiga s/n, 4715-330 Braga, Portugal
| | - Oleksandr Bondarchuk
- INL
− International Iberian Nanotechnology Laboratory, Advanced
Electron Microscopy, Imaging and Spectroscopy Facility, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal
| | - Jana B. Nieder
- INL
− International Iberian Nanotechnology Laboratory, Ultrafast
Bio- and Nanophotonics group, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal
| | - Bruno Romeira
- INL
− International Iberian Nanotechnology Laboratory, Ultrafast
Bio- and Nanophotonics group, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal
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5
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Parakh M, Ramaswamy P, Devkota S, Kuchoor H, Dawkins K, Iyer S. Passivation efficacy study of Al 2O 3dielectric on self-catalyzed molecular beam epitaxially grown GaAs 1-xSb xnanowires. NANOTECHNOLOGY 2022; 33:315602. [PMID: 35468592 DOI: 10.1088/1361-6528/ac69f8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 04/22/2022] [Indexed: 06/14/2023]
Abstract
This work evaluates the passivation efficacy of thermal atomic layer deposited (ALD) Al2O3dielectric layer on self-catalyzed GaAs1-xSbxnanowires (NWs) grown using molecular beam epitaxy. A detailed assessment of surface chemical composition and optical properties of Al2O3passivated NWs with and without prior sulfur treatment were studied and compared to as-grown samples using x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and low-temperature photoluminescence (PL) spectroscopy. The XPS measurements reveal that prior sulfur treatment followed by Al2O3ALD deposition abates III-V native oxides from the NW surface. However, the degradation in 4K-PL intensity by an order of magnitude observed for NWs with Al2O3shell layer compared to the as-grown NWs, irrespective of prior sulfur treatment, suggests the formation of defect states at the NW/dielectric interface contributing to non-radiative recombination centers. This is corroborated by the Raman spectral broadening of LO and TO Raman modes, increased background scattering, and redshift observed for Al2O3deposited NWs relative to the as-grown. Thus, our work seems to indicate the unsuitability of ALD deposited Al2O3as a passivation layer for GaAsSb NWs.
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Affiliation(s)
- Mehul Parakh
- Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro NC, 27401, United States of Americ a
| | - Priyanka Ramaswamy
- Department of Electrical and Computer Engineering, North Carolina A&T State University, Greensboro NC, 27411, United States of America
| | - Shisir Devkota
- Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro NC, 27401, United States of Americ a
| | - Hirandeep Kuchoor
- Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro NC, 27401, United States of Americ a
| | - Kendall Dawkins
- Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro NC, 27401, United States of Americ a
| | - Shanthi Iyer
- Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro NC, 27401, United States of Americ a
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6
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Zeng X, Zhang W, Zou X, Su X, Yartsev A, Borgström MT. In situpassivation of Ga xIn (1-x)P nanowires using radial Al yIn (1-y)P shells grown by MOVPE. NANOTECHNOLOGY 2021; 32:425705. [PMID: 34229309 DOI: 10.1088/1361-6528/ac1198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
GaxIn(1-x)P nanowires with suitable bandgap (1.35-2.26 eV) ranging from the visible to near-infrared wavelength have great potential in optoelectronic applications. Due to the large surface-to-volume ratio of nanowires, the surface states become a pronounced factor affecting device performance. In this work, we performed a systematic study of GaxIn(1-x)P nanowires' surface passivation, utilizing AlyIn(1-y)P shells grownin situby using a metal-organic vapor phase epitaxy system. Time-resolved photoinduced luminescence and time-resolved THz spectroscopy measurements were performed to study the nanowires' carrier recombination processes. Compared to the bare Ga0.41In0.59P nanowires without shells, the hole and electron lifetime of the nanowires with the Al0.36In0.64P shells are found to be larger by 40 and 1.1 times, respectively, demonstrating effective surface passivation of trap states. When shells with higher Al composition were grown, both lifetimes of free holes and electrons decreased prominently. We attribute the acceleration of PL decay to an increase in the trap states' density due to the formation of defects, including the polycrystalline and oxidized amorphous areas in these samples. Furthermore, in a separate set of samples, we varied the shell thickness. We observed that a certain shell thickness of approximately ∼20 nm is needed for efficient passivation of Ga0.31In0.69P nanowires. The photoconductivity of the sample with a shell thickness of 23 nm decays 10 times slower compared with that of the bare core nanowires. We concluded that both the hole and electron trapping and the overall charge recombination in GaxIn(1-x)P nanowires can be substantially passivated through growing an AlyIn(1-y)P shell with appropriate Al composition and thickness. Therefore, we have developed an effectivein situsurface passivation of GaxIn(1-x)P nanowires by use of AlyIn(1-y)P shells, paving the way to high-performance GaxIn(1-x)P nanowires optoelectronic devices.
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Affiliation(s)
- Xulu Zeng
- Solid State Physics, NanoLund, Lund University, PO Box 118, SE-22100 Lund, Sweden
| | - Wei Zhang
- School of Physics and Electronic Engineering, Guangzhou University, 510006 Guangzhou, People's Republic of China
- Division of Chemical Physics, NanoLund, Lund University, PO Box 124, SE-22100 Lund, Sweden
| | - Xianshao Zou
- Division of Chemical Physics, NanoLund, Lund University, PO Box 124, SE-22100 Lund, Sweden
| | - Xiaojun Su
- Division of Chemical Physics, NanoLund, Lund University, PO Box 124, SE-22100 Lund, Sweden
| | - Arkady Yartsev
- Division of Chemical Physics, NanoLund, Lund University, PO Box 124, SE-22100 Lund, Sweden
| | - Magnus T Borgström
- Solid State Physics, NanoLund, Lund University, PO Box 118, SE-22100 Lund, Sweden
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7
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Chellu A, Koivusalo E, Raappana M, Ranta S, Polojärvi V, Tukiainen A, Lahtonen K, Saari J, Valden M, Seppänen H, Lipsanen H, Guina M, Hakkarainen T. GaAs surface passivation for InAs/GaAs quantum dot based nanophotonic devices. NANOTECHNOLOGY 2021; 32:130001. [PMID: 33276349 DOI: 10.1088/1361-6528/abd0b4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Several passivation techniques are developed and compared in terms of their ability to preserve the optical properties of close-to-surface InAs/GaAs quantum dots (QDs). In particular, the influence of N-passivation by hydrazine chemical treatment, N-passivation by hydrazine followed by atomic layer deposition (ALD) of AlO x and use of AlN x deposited by plasma-enhanced ALD are reported. The effectiveness of the passivation is benchmarked by measuring the emission linewidths and decay rates of photo-carriers for the near-surface QDs. All three passivation mechanisms resulted in reducing the oxidation of Ga and As atoms at the GaAs surface and consequently in enhancing the room-temperature photoluminescence (PL) intensity. However, long-term stability of the passivation effect is exhibited only by the hydrazine + AlO x process and more significantly by the AlN x method. Moreover, in contrast to the results obtained from hydrazine-based methods, the AlN x passivation strongly reduces the spectral diffusion of the QD exciton lines caused by charge fluctuations at the GaAs surface. The AlN x passivation is found to reduce the surface recombination velocity by three orders of magnitude (corresponding to an increase of room-temperature PL signal by ∼1030 times). The reduction of surface recombination velocity is demonstrated on surface-sensitive GaAs (100) and the passivating effect is stable for more than one year. This effective method of passivation, coupled with its stability in time, is extremely promising for practical device applications such as quantum light sources based on InAs/GaAs QDs positioned in small-volume photonic cavities and hence in the proximity of GaAs-air interface.
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Affiliation(s)
- Abhiroop Chellu
- Optoelectronics Research Centre, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Eero Koivusalo
- Optoelectronics Research Centre, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Marianna Raappana
- Optoelectronics Research Centre, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Sanna Ranta
- Optoelectronics Research Centre, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Ville Polojärvi
- Optoelectronics Research Centre, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Antti Tukiainen
- Optoelectronics Research Centre, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Kimmo Lahtonen
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, FI-33720, Finland
| | - Jesse Saari
- Surface Science Group, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Mika Valden
- Surface Science Group, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Heli Seppänen
- Department of Electronics and Nanoengineering, Aalto University, Espoo, FI-02150, Finland
| | - Harri Lipsanen
- Department of Electronics and Nanoengineering, Aalto University, Espoo, FI-02150, Finland
| | - Mircea Guina
- Optoelectronics Research Centre, Physics Unit, Tampere University, Tampere, FI-33720, Finland
| | - Teemu Hakkarainen
- Optoelectronics Research Centre, Physics Unit, Tampere University, Tampere, FI-33720, Finland
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8
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Andreoli L, Porte X, Heuser T, Große J, Moeglen-Paget B, Furfaro L, Reitzenstein S, Brunner D. Optical pumping of quantum dot micropillar lasers. OPTICS EXPRESS 2021; 29:9084-9097. [PMID: 33820344 DOI: 10.1364/oe.417063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/09/2021] [Indexed: 06/12/2023]
Abstract
Arrays of quantum dot micropillar lasers are an attractive technology platform for various applications in the wider field of nanophotonics. Of particular interest is the potential efficiency enhancement as a consequence of cavity quantum electrodynamics effects, which makes them prime candidates for next generation photonic neurons in neural network hardware. However, particularly for optical pumping, their power-conversion efficiency can be very low. Here we perform an in-depth experimental analysis of quantum dot microlasers and investigate their input-output relationship over a wide range of optical pumping conditions. We find that the current energy efficiency limitation is caused by disadvantageous optical pumping concepts and by a low exciton conversion efficiency. Our results indicate that for non-resonant pumping into the GaAs matrix (wetting layer), 3.4% (0.6%) of the optical pump is converted into lasing-relevant excitons, and of those only 2% (0.75%) provide gain to the lasing transition. Based on our findings, we propose to improve the pumping efficiency by orders of magnitude by increasing the aluminium content of the AlGaAs/GaAs mirror pairs in the upper Bragg reflector.
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9
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André Y, Isik Goktas N, Monier G, Hijazi H, Mehdi H, Bougerol C, Bideux L, Trassoudaine A, Paget D, Leymarie J, Gil E, Robert-Goumet C, LaPierre RR. Optical and structural analysis of ultra-long GaAs nanowires after nitrogen-plasma passivation. NANO EXPRESS 2020. [DOI: 10.1088/2632-959x/aba7f1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
The structural and optical properties of individual ultra-long GaAs nanowires (NWs) were studied after different nitrogen passivation process conditions. The surface morphology of the NWs after passivation was characterized by high resolution transmission electron microscopy (HRTEM) and high angle annular dark field (HAADF) imaging. Electron energy loss spectroscopy (EELS) confirmed the presence of nitrogen on the NW surface. Micro-photoluminescence (μ-PL) on single NWs indicated an increase of the luminescence intensity upon passivation. This work reveals the efficacy of a plasma passivation process on complex nanometer-scale morphologies.
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10
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Zou X, Li C, Su X, Liu Y, Finkelstein-Shapiro D, Zhang W, Yartsev A. Carrier Recombination Processes in GaAs Wafers Passivated by Wet Nitridation. ACS APPLIED MATERIALS & INTERFACES 2020; 12:28360-28367. [PMID: 32469493 PMCID: PMC7467545 DOI: 10.1021/acsami.0c04892] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
As one of the successful approaches to GaAs surface passivation, wet-chemical nitridation is applied here to relate the effect of surface passivation to carrier recombination processes in bulk GaAs. By combining time-resolved photoluminescence and optical pump-THz probe measurements, we found that surface hole trapping dominates the decay of photoluminescence, while photoconductivity dynamics is limited by surface electron trapping. Compared to untreated sample dynamics, the optimized nitridation reduces hole- and electron-trapping rate by at least 2.6 and 3 times, respectively. Our results indicate that under ambient conditions, recovery of the fast hole trapping due to the oxide regrowth at the deoxidized GaAs surface takes tens of hours, while it is effectively inhibited by surface nitridation. Our study demonstrates that surface nitridation stabilizes the GaAs surface via reduction of both electron- and hole-trapping rates, which results in chemical and electronical passivation of the bulk GaAs surface.
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Affiliation(s)
- Xianshao Zou
- School
of Physics and Electronic Engineering, Guangzhou
University, 510006 Guangzhou, China
- NanoLund
and Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Chuanshuai Li
- NanoLund
and Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Xiaojun Su
- NanoLund
and Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Yuchen Liu
- NanoLund
and Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | | | - Wei Zhang
- School
of Physics and Electronic Engineering, Guangzhou
University, 510006 Guangzhou, China
| | - Arkady Yartsev
- NanoLund
and Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
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11
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Ma L, Wang P, Yin X, Liang Y, Liu S, Li L, Pan D, Yao Z, Liu B, Zhao J. Enhancing the light emission of GaAs nanowires by pressure-modulated charge transfer. NANOSCALE ADVANCES 2020; 2:2558-2563. [PMID: 36133362 PMCID: PMC9417809 DOI: 10.1039/d0na00188k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 04/15/2020] [Indexed: 06/16/2023]
Abstract
Strong non-radiative surface recombination in GaAs nanowires heavily blocks their applications as nanoscale optoelectronic devices. Pressure can effectively affect the surface recombination behaviors through tuning interactions between the surface of nanomaterials and the medium environment. Here, we report the pressure-induced light emission enhancement in GaAs nanowires via in situ high pressure photoluminescence measurements with nitrogen as the pressure transmitting medium. In the pressure range from 0 to 2.2 GPa, the photoluminescence intensity dramatically increases with increasing pressure. Above 2.2 GPa, the band gap transition from direct to indirect results in a sudden decrease in the photoluminescence intensity. Photoluminescence enhancement in GaAs nanowires also shows the pressure-dependent reversibility. The pressure-enhanced charge transfer effect between nitrogen molecules and the GaAs nanowire surface has been revealed according to first-principles calculations, which results in the reduction of surface states and the light-emission enhancement in GaAs NWs. Our study can provide a potential route for optimizing nanoscale functional devices.
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Affiliation(s)
- Luoman Ma
- State Key Laboratory of Superhard Materials, Jilin University Changchun 130012 China
| | - Peng Wang
- State Key Laboratory of Superhard Materials, Jilin University Changchun 130012 China
| | - Xuetong Yin
- State Key Laboratory of Superhard Materials, Jilin University Changchun 130012 China
| | - Yilan Liang
- State Key Laboratory of Superhard Materials, Jilin University Changchun 130012 China
| | - Shuang Liu
- State Key Laboratory of Superhard Materials, Jilin University Changchun 130012 China
| | - Lixia Li
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences P.O. Box 912 Beijing 100083 China
| | - Dong Pan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences P.O. Box 912 Beijing 100083 China
| | - Zhen Yao
- State Key Laboratory of Superhard Materials, Jilin University Changchun 130012 China
| | - Bingbing Liu
- State Key Laboratory of Superhard Materials, Jilin University Changchun 130012 China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences P.O. Box 912 Beijing 100083 China
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Yan X, Liu H, Sibirev N, Zhang X, Ren X. Performance Enhancement of Ultra-Thin Nanowire Array Solar Cells by Bottom Reflectivity Engineering. NANOMATERIALS 2020; 10:nano10020184. [PMID: 31973099 PMCID: PMC7074864 DOI: 10.3390/nano10020184] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/18/2020] [Accepted: 01/18/2020] [Indexed: 11/16/2022]
Abstract
A bottom-reflectivity-enhanced ultra-thin nanowire array solar cell is proposed and studied by 3D optoelectronic simulations. By inserting a small-index MgF2 layer between the polymer and substrate, the absorption is significantly improved over a broad wavelength range due to the strong reabsorption of light reflected at the polymer/MgF2 interface. With a 5 nm-thick MgF2 layer, the GaAs nanowire array solar cell with a height of 0.4-1 μm yields a remarkable conversion efficiency ranging from 14% to 15.6%, significantly higher than conventional structures with a much larger height. Moreover, by inserting the MgF2 layer between the substrate and a part of the nanowire, in addition to between the substrate and polymer, the absorption of substrate right below the nanowire is further suppressed, leading to an optimal efficiency of 15.9%, 18%, and 5.4% for 1 μm-high GaAs, InP, and Si nanowire solar cells, respectively. This work provides a simple and universal way to achieve low-cost high-performance nanoscale solar cells.
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Affiliation(s)
- Xin Yan
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China; (X.Y.); (H.L.); (X.R.)
| | - Haoran Liu
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China; (X.Y.); (H.L.); (X.R.)
| | | | - Xia Zhang
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China; (X.Y.); (H.L.); (X.R.)
- Correspondence:
| | - Xiaomin Ren
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China; (X.Y.); (H.L.); (X.R.)
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13
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Himwas C, Collin S, Chen HL, Patriarche G, Oehler F, Travers L, Saket O, Julien FH, Harmand JC, Tchernycheva M. Correlated optical and structural analyses of individual GaAsP/GaP core-shell nanowires. NANOTECHNOLOGY 2019; 30:304001. [PMID: 30965307 DOI: 10.1088/1361-6528/ab1760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report on the structural and optical properties of GaAs0.7P0.3/GaP core-shell nanowires (NWs) for future photovoltaic applications. The NWs are grown by self-catalyzed molecular beam epitaxy. Scanning transmission electron microscopy (STEM) analyses demonstrate that the GaAsP NW core develops an inverse-tapered shape with a formation of an unintentional GaAsP shell having a lower P content. Without surface passivation, this unintentional shell produces no luminescence because of strong surface recombination. However, passivation of the surface with a GaP shell leads to the appearance of a secondary peak in the luminescence spectrum arising from this unintentional shell. The attribution of the luminescence peaks is confirmed by correlated cathodoluminescence and STEM analyses of the same NW.
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Affiliation(s)
- C Himwas
- Centre de Nanosciences et de Nanotechnologies, UMR 9001 CNRS, Univ. Paris Sud, Univ. Paris-Saclay, 10 Boulevard Thomas Gobert, F-91120 Palaiseau Cedex, France. Semiconductor Device Research Laboratory, Department of Electrical Engineering, Faculty of Engineering, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
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14
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Alekseev PA, Sharov VA, Dunaevskiy MS, Kirilenko DA, Ilkiv IV, Reznik RR, Cirlin GE, Berkovits VL. Control of Conductivity of In xGa 1-xAs Nanowires by Applied Tension and Surface States. NANO LETTERS 2019; 19:4463-4469. [PMID: 31203633 DOI: 10.1021/acs.nanolett.9b01264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The electronic properties of semiconductor AIIIBV nanowires (NWs) due to their high surface/volume ratio can be effectively controlled by NW strain and surface electronic states. We study the effect of applied tension on the conductivity of wurtzite InxGa1-xAs (x ∼ 0.8) NWs. Experimentally, conductive atomic force microscopy is used to measure the I-V curves of vertically standing NWs covered by native oxide. To apply tension, the microscope probe touching the NW side is shifted laterally to produce a tensile strain in the NW. The NW strain significantly increases the forward current in the measured I-V curves. When the strain reaches 4%, the I-V curve becomes almost linear, and the forward current increases by 3 orders of magnitude. In the latter case, the tensile strain is supposed to shift the conduction band minima below the Fermi level, whose position, in turn, is fixed by surface states. Consequently, the surface conductivity channel appears. The observed effects confirm that the excess surface arsenic is responsible for the Fermi level pinning at oxidized surfaces of III-As NWs.
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Affiliation(s)
| | - Vladislav A Sharov
- Ioffe Institute , Saint Petersburg 194021 , Russia
- Saint-Petersburg Academic University , Saint Petersburg 194021 , Russia
| | | | | | - Igor V Ilkiv
- Saint-Petersburg Academic University , Saint Petersburg 194021 , Russia
| | | | - George E Cirlin
- Saint-Petersburg Academic University , Saint Petersburg 194021 , Russia
- ITMO University , Saint Petersburg 197101 , Russia
- Saint Petersburg Electrotechnical University LETI , Saint Petersburg 197376 , Russia
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15
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Memory phototransistors based on exponential-association photoelectric conversion law. Nat Commun 2019; 10:1294. [PMID: 30894530 PMCID: PMC6426936 DOI: 10.1038/s41467-019-09206-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 02/20/2019] [Indexed: 11/23/2022] Open
Abstract
Ultraweak light detectors have wide-ranging important applications such as astronomical observation, remote sensing, laser ranging, and night vision. Current commercial ultraweak light detectors are commonly based on a photomultiplier tube or an avalanche photodiode, and they are incompatible with microelectronic devices for digital imaging applications, because of their high operating voltage and bulky size. Herein, we develop a memory phototransistor for ultraweak light detection, by exploiting the charge-storage accumulative effect in CdS nanoribbon. The memory phototransistors break the power law of traditional photodetectors and follow a time-dependent exponential-association photoelectric conversion law. Significantly, the memory phototransistors exhibit ultrahigh responsivity of 3.8 × 109 A W−1 and detectivity of 7.7 × 1022 Jones. As a result, the memory phototransistors are able to detect ultraweak light of 6 nW cm−2 with an extremely high sensitivity of 4 × 107. The proposed memory phototransistors offer a design concept for ultraweak light sensing devices. CdS nanostructures can enable memory based photodetection by charge-storage accumulative effect. Here, the authors report CdS nanoribbons-based memory phototransistors with high responsivity of 3.8 × 109 A/W and detectivity of 7.7 × 1022 Jones that can detect weak light of 6 nW/cm2.
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16
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Alanis JA, Lysevych M, Burgess T, Saxena D, Mokkapati S, Skalsky S, Tang X, Mitchell P, Walton AS, Tan HH, Jagadish C, Parkinson P. Optical Study of p-Doping in GaAs Nanowires for Low-Threshold and High-Yield Lasing. NANO LETTERS 2019; 19:362-368. [PMID: 30525674 DOI: 10.1021/acs.nanolett.8b04048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Semiconductor nanowires suffer from significant non-radiative surface recombination; however, heavy p-type doping has proven to be a viable option to increase the radiative recombination rate and, hence, quantum efficiency of emission, allowing the demonstration of room-temperature lasing. Using a large-scale optical technique, we have studied Zn-doped GaAs nanowires to understand and quantify the effect of doping on growth and lasing properties. We measure the non-radiative recombination rate ( knr) to be (0.14 ± 0.04) ps-1 by modeling the internal quantum efficiency (IQE) as a function of doping level. By applying a correlative method, we identify doping and nanowire length as key controllable parameters determining lasing behavior, with reliable room-temperature lasing occurring for p ≳ 3 × 1018 cm-3 and lengths of ≳4 μm. We report a best-in-class core-only near-infrared nanowire lasing threshold of ∼10 μJ cm-2, and using a data-led filtering step, we present a method to simply identify subsets of nanowires with over 90% lasing yield.
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Affiliation(s)
| | | | | | - Dhruv Saxena
- The Blackett Laboratory, Department of Physics , Imperial College London , London SW7 2AZ , United Kingdom
| | - Sudha Mokkapati
- School of Physics and Astronomy and the Institute for Compound Semiconductors , Cardiff University , Cardiff , CF10 3AT , United Kingdom
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17
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Alekseev PA, Dunaevskiy MS, Cirlin GE, Reznik RR, Smirnov AN, Kirilenko DA, Davydov VY, Berkovits VL. Unified mechanism of the surface Fermi level pinning in III-As nanowires. NANOTECHNOLOGY 2018; 29:314003. [PMID: 29757753 DOI: 10.1088/1361-6528/aac480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Fermi level pinning at the oxidized (110) surfaces of III-As nanowires (GaAs, InAs, InGaAs, AlGaAs) is studied. Using scanning gradient Kelvin probe microscopy, we show that the Fermi level at oxidized cleavage surfaces of ternary Al x Ga1-x As (0 ≤ x ≤ 0.45) and Ga x In1-x As (0 ≤ x ≤ 1) alloys is pinned at the same position of 4.8 ± 0.1 eV with regard to the vacuum level. The finding implies a unified mechanism of the Fermi level pinning for such surfaces. Further investigation, performed by Raman scattering and photoluminescence spectroscopy, shows that photooxidation of the Al x Ga1-x As and Ga x In1-x As nanowires leads to the accumulation of an excess of arsenic on their crystal surfaces which is accompanied by a strong decrease of the band-edge photoluminescence intensity. We conclude that the surface excess arsenic in crystalline or amorphous forms is responsible for the Fermi level pinning at oxidized (110) surfaces of III-As nanowires.
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18
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19
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Chalcogen passivation: an in-situ method to manipulate the morphology and electrical property of GaAs nanowires. Sci Rep 2018; 8:6928. [PMID: 29720609 PMCID: PMC5932019 DOI: 10.1038/s41598-018-25209-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/06/2018] [Indexed: 01/20/2023] Open
Abstract
Recently, owing to the large surface-area-to-volume ratio of nanowires (NWs), manipulation of their surface states becomes technologically important and being investigated for various applications. Here, an in-situ surfactant-assisted chemical vapor deposition is developed with various chalcogens (e.g. S, Se and Te) as the passivators to enhance the NW growth and to manipulate the controllable p-n conductivity switching of fabricated NW devices. Due to the optimal size effect and electronegativity matching, Se is observed to provide the best NW surface passivation in diminishing the space charge depletion effect induced by the oxide shell and yielding the less p-type (i.e. inversion) or even insulating conductivity, as compared with S delivering the intense p-type conductivity for thin NWs with the diameter of ~30 nm. Te does not only provide the surface passivation, but also dopes the NW surface into n-type conductivity by donating electrons. All of the results can be extended to other kinds of NWs with similar surface effects, resulting in careful device design considerations with appropriate surface passivation for achieving the optimal NW device performances.
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20
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Fang X, Wei Z, Fang D, Chu X, Tang J, Wang D, Wang X, Li J, Li Y, Yao B, Wang X, Chen R. Surface State Passivation and Optical Properties Investigation of GaSb via Nitrogen Plasma Treatment. ACS OMEGA 2018; 3:4412-4417. [PMID: 31458667 PMCID: PMC6641701 DOI: 10.1021/acsomega.7b01783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/19/2018] [Indexed: 06/10/2023]
Abstract
GaSb is one of the most suitable semiconductors for optoelectronic devices operating in the mid-infrared range. However, the existence of GaSb surface states has dramatically limited the performance of these devices. Herein, a controllable nitrogen passivation approach is proposed for GaSb. The surface states and optical properties of GaSb were found to depend on the N passivation conditions. Varying the plasma power during passivation modified the chemical bonds of the GaSb surface, which influenced the emission efficiency. X-ray photoelectron spectroscopy was used to quantitatively demonstrate that the GaSb oxide layer was removed via treatment at a plasma power of 100 W. After nitrogen passivation, the samples exhibited enhanced emission. Free exciton emission was the main factor leading to this enhanced luminescence. An energy band model for the surface states is used to explain the carrier radiative recombination processes. This nitrogen passivation approach can suppress surface states and improve the surface quality of GaSb-based materials and devices. The enhancement in exciton-related emission by this simple approach is important for improving the performance of GaSb-based optoelectronic devices.
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Affiliation(s)
- Xuan Fang
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Zhipeng Wei
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Dan Fang
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Xueying Chu
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Jilong Tang
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Dengkui Wang
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Xinwei Wang
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Jinhua Li
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Yongfeng Li
- Key
Laboratory of Physics and Technology for Advanced Batteries, Ministry
of Education, College of Physics, Jilin
University, Changchun 130012, P. R. China
| | - Bin Yao
- Key
Laboratory of Physics and Technology for Advanced Batteries, Ministry
of Education, College of Physics, Jilin
University, Changchun 130012, P. R. China
| | - Xiaohua Wang
- State
Key Laboratory of High Power Semiconductor Lasers, School of Science, Changchun University of Science and Technology, 7089 Wei-Xing Road, Changchun 130022, P. R. China
| | - Rui Chen
- Department
of Electrical and Electronic Engineering, South University of Science and Technology of China, Shenzhen, Guangdong 518055, P. R. China
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21
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Chen W, Wen X, Yang J, Latzel M, Patterson R, Huang S, Shrestha S, Jia B, Moss DJ, Christiansen S, Conibeer G. Free charges versus excitons: photoluminescence investigation of InGaN/GaN multiple quantum well nanorods and their planar counterparts. NANOSCALE 2018; 10:5358-5365. [PMID: 29509196 DOI: 10.1039/c7nr07567g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
InGaN/GaN multiple quantum well (MQW) nanorods have demonstrated significantly improved optical and electronic properties compared to their planar counterparts. However, the exact nature of the processes whereby nanorod structures impact the optical properties of quantum wells is not well understood, even though a variety of mechanisms have been proposed. We performed nanoscale spatially resolved, steady-state, and time-resolved photoluminescence (PL) experiments confirming that photoexcited electrons and holes are strongly bound by Coulomb interactions (i.e., excitons) in planar MQWs due to the large exciton binding energy in InGaN quantum wells. In contrast, free electron-hole recombination becomes the dominant mechanism in nanorods, which is ascribed to efficient exciton dissociation. The nanorod sidewall provides an effective pathway for exciton dissociation that significantly improves the optical performance of InGaN/GaN MQWs. We also confirm that surface treatment of nanorod sidewalls has an impact on exciton dissociation. Our results provide new insights into excitonic and charge carrier dynamics of quantum confined materials as well as the influence of surface states.
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Affiliation(s)
- Weijian Chen
- Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Sydney 2052, Australia.
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22
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Chen X, Xia N, Yang Z, Gong F, Wei Z, Wang D, Tang J, Fang X, Fang D, Liao L. Analysis of the influence and mechanism of sulfur passivation on the dark current of a single GaAs nanowire photodetector. NANOTECHNOLOGY 2018; 29:095201. [PMID: 29297469 DOI: 10.1088/1361-6528/aaa4d6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanowire photodetectors, which have the advantages of fast response and high photoelectric conversion efficiency, can be widely applied in various industries. However, the rich surface states result in large dark current and can hinder the development of high-performance nanowire photodetectors. In this paper, the influence and mechanism of sulfur surface passivation on the dark current of a single GaAs nanowire photodetector have been studied. The dark current is significantly reduced by about 30 times after surface passivation. We confirm that the origin of the reduction of dark current is the decrease in the surface state density. As a result, a single GaAs nanowire photodetector with low dark current of 7.18 × 10-2 pA and high detectivity of 9.04 × 1012 cmHz0.5W-1 has been achieved. A simple and convenient way to realize high-performance GaAs-based photodetectors has been proposed.
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Affiliation(s)
- Xue Chen
- State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, People's Republic of China
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23
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Dunaevskiy M, Geydt P, Lähderanta E, Alekseev P, Haggrén T, Kakko JP, Jiang H, Lipsanen H. Young's Modulus of Wurtzite and Zinc Blende InP Nanowires. NANO LETTERS 2017; 17:3441-3446. [PMID: 28534623 DOI: 10.1021/acs.nanolett.7b00312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The Young's modulus of thin conical InP nanowires with either wurtzite or mixed "zinc blende/wurtzite" structures was measured. It has been shown that the value of Young's modulus obtained for wurtzite InP nanowires (E[0001] = 130 ± 30 GPa) was similar to the theoretically predicted value for the wurtzite InP material (E[0001] = 120 ± 10 GPa). The Young's modulus of mixed "zinc blende/wurtzite" InP nanowires (E[111] = 65 ± 10 GPa) appeared to be 40% less than the theoretically predicted value for the zinc blende InP material (E[111] = 110 GPa). An advanced method for measuring the Young's modulus of thin and flexible nanostructures is proposed. It consists of measuring the flexibility (the inverse of stiffness) profiles 1/k(x) by the scanning probe microscopy with precise control of loading force in nanonewton range followed by simulations.
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Affiliation(s)
- Mikhail Dunaevskiy
- Ioffe Institute , Saint Petersburg 194021, Russia
- ITMO University , Saint Petersburg 197101, Russia
| | - Pavel Geydt
- Lappeenranta University of Technology , P.O. Box 20, Lappeenranta FI-53851, Finland
| | - Erkki Lähderanta
- Lappeenranta University of Technology , P.O. Box 20, Lappeenranta FI-53851, Finland
| | | | - Tuomas Haggrén
- Aalto University , P.O. Box 15100, Espoo FI-00076, Finland
| | | | - Hua Jiang
- Aalto University , P.O. Box 15100, Espoo FI-00076, Finland
| | - Harri Lipsanen
- Aalto University , P.O. Box 15100, Espoo FI-00076, Finland
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24
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Guan X, Becdelievre J, Benali A, Botella C, Grenet G, Regreny P, Chauvin N, Blanchard NP, Jaurand X, Saint-Girons G, Bachelet R, Gendry M, Penuelas J. GaAs nanowires with oxidation-proof arsenic capping for the growth of an epitaxial shell. NANOSCALE 2016; 8:15637-15644. [PMID: 27513669 DOI: 10.1039/c6nr04817j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We propose an arsenic-capping/decapping method, allowing the growth of an epitaxial shell around the GaAs nanowire (NW) core which is exposed to an ambient atmosphere, and without the introduction of impurities. Self-catalyzed GaAs NW arrays were firstly grown on Si(111) substrates by solid-source molecular beam epitaxy. Aiming for protecting the active surface of the GaAs NW core, the arsenic-capping/decapping method has been applied. To validate the effect of this method, different core/shell NWs have been fabricated. Analyses highlight the benefit of the As capping-decapping method for further epitaxial shell growth: an epitaxial shell with a smooth surface is achieved in the case of As-capped-decapped GaAs NWs, comparable to the in situ grown GaAs/AlGaAs NWs. This As capping method opens a way for the epitaxial growth of heterogeneous material shells such as functional oxides using different reactors.
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Affiliation(s)
- X Guan
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - J Becdelievre
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - A Benali
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - C Botella
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - G Grenet
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - P Regreny
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - N Chauvin
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, INSA de Lyon, 7 avenue Jean Capelle, F-69621 Villeurbanne, France.
| | - N P Blanchard
- Institut Lumière Matière (ILM), UMR5306 Université Lyon 1-CNRS Université de Lyon, 69622 Villeurbanne cedex, France
| | - X Jaurand
- Centre Technologique des Microstructures, Université Claude Bernard Lyon1, 5 rue Raphael Dubois-Bâtiment Darwin B, F-69622, Villeurbanne Cedex, France
| | - G Saint-Girons
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - R Bachelet
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - M Gendry
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
| | - J Penuelas
- Université de Lyon, Institut des Nanotechnologies de Lyon - UMR 5270 - CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully cedex, France
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25
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Mokkapati S, Jagadish C. Review on photonic properties of nanowires for photovoltaics. OPTICS EXPRESS 2016; 24:17345-17358. [PMID: 27464182 DOI: 10.1364/oe.24.017345] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
III-V semiconductor nanowires behave as optical antennae because of their shape anisotropy and high refractive index. The antennae like behavior modifies the absorption and emission properties of nanowires compared to planar materials. Nanowires absorb light more efficiently compared to an equivalent volume planar material, leading to higher short circuit current densities. The modified emission from the nanowires has the potential to increase the open circuit voltage from nanowire solar cells compared to planar solar cells. In order to achieve high efficiency nanowire solar cells it is essential to control the surface state density and doping in nanowires. We review the physics of nanowire solar cells and progress made in addressing the surface recombination and doping of nanowires, with emphasis on GaAs and InP materials.
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26
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Ishikawa F, Akamatsu Y, Watanabe K, Uesugi F, Asahina S, Jahn U, Shimomura S. Metamorphic GaAs/GaAsBi Heterostructured Nanowires. NANO LETTERS 2015; 15:7265-7272. [PMID: 26501188 DOI: 10.1021/acs.nanolett.5b02316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
GaAs/GaAsBi coaxial multishell nanowires were grown by molecular beam epitaxy. Introducing Bi results in a characteristic nanowire surface morphology with strong roughening. Elemental mappings clearly show the formation of the GaAsBi shell with inhomogeneous Bi distributions within the layer surrounded by the outermost GaAs, having a strong structural disorder at the wire surface. The nanowire exhibits a predominantly ZB structure from the bottom to the middle part. The polytipic WZ structure creates denser twin defects in the upper part than in the bottom and middle parts of the nanowire. We observe room temperature cathodoluminescence from the GaAsBi nanowires with a broad spectral line shape between 1.1 and 1.5 eV, accompanied by multiple peaks. A distinct energy peak at 1.24 eV agrees well with the energy of the reduced GaAsBi alloy band gap by the introduction of 2% Bi. The existence of localized states energetically and spatially dispersed throughout the NW are indicated from the low temperature cathodoluminescence spectra and images, resulting in the observed luminescence spectra characterized by large line widths at low temperatures as well as by the appearance of multiple peaks at high temperatures and for high excitation powers.
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Affiliation(s)
- Fumitaro Ishikawa
- Graduate School of Science and Engineering, Ehime University , 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Yoshihiko Akamatsu
- Graduate School of Science and Engineering, Ehime University , 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Kentaro Watanabe
- WPI Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Fumihiko Uesugi
- Transmission Electron Microscopy Station, National Institute for Materials Science , 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Shunsuke Asahina
- SM Business Unit, JEOL Ltd. , 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan
| | - Uwe Jahn
- Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany
| | - Satoshi Shimomura
- Graduate School of Science and Engineering, Ehime University , 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
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Chen SL, Chen WM, Ishikawa F, Buyanova IA. Suppression of non-radiative surface recombination by N incorporation in GaAs/GaNAs core/shell nanowires. Sci Rep 2015; 5:11653. [PMID: 26100755 PMCID: PMC4477342 DOI: 10.1038/srep11653] [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: 03/02/2015] [Accepted: 05/05/2015] [Indexed: 11/15/2022] Open
Abstract
III-V semiconductor nanowires (NWs) such as GaAs NWs form an interesting artificial materials system promising for applications in advanced optoelectronic and photonic devices, thanks to the advantages offered by the 1D architecture and the possibility to combine it with the main-stream silicon technology. Alloying of GaAs with nitrogen can further enhance performance and extend device functionality via band-structure and lattice engineering. However, due to a large surface-to-volume ratio, III-V NWs suffer from severe non-radiative carrier recombination at/near NWs surfaces that significantly degrades optical quality. Here we show that increasing nitrogen composition in novel GaAs/GaNAs core/shell NWs can strongly suppress the detrimental surface recombination. This conclusion is based on our experimental finding that lifetimes of photo-generated free excitons and free carriers increase with increasing N composition, as revealed from our time-resolved photoluminescence (PL) studies. This is accompanied by a sizable enhancement in the PL intensity of the GaAs/GaNAs core/shell NWs at room temperature. The observed N-induced suppression of the surface recombination is concluded to be a result of an N-induced modification of the surface states that are responsible for the nonradiative recombination. Our results, therefore, demonstrate the great potential of incorporating GaNAs in III-V NWs to achieve efficient nano-scale light emitters.
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Affiliation(s)
- Shula L Chen
- Department of Physics, Chemistry and Biology, Linköping University, 58183, Linköping, Sweden
| | - Weimin M Chen
- Department of Physics, Chemistry and Biology, Linköping University, 58183, Linköping, Sweden
| | - Fumitaro Ishikawa
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Irina A Buyanova
- Department of Physics, Chemistry and Biology, Linköping University, 58183, Linköping, Sweden
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