1
|
Freddi S, Achilli S, Soave R, Pagliara S, Drera G, De Poli A, De Nicola F, De Crescenzi M, Castrucci P, Sangaletti L. Dramatic efficiency boost of single-walled carbon nanotube-silicon hybrid solar cells through exposure to ppm nitrogen dioxide in air: An ab-initio assessment of the measured device performances. J Colloid Interface Sci 2020; 566:60-68. [PMID: 31986309 DOI: 10.1016/j.jcis.2020.01.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/19/2019] [Accepted: 01/13/2020] [Indexed: 11/16/2022]
Abstract
We observed a 73% enhancement of the power conversion efficiency (PCE) of a photovoltaic cell based on a single wall carbon nanotube/Si hybrid junction after exposing the device to a limited amount (10 ppm) of NO2 diluted in dry air. On the basis of a computational modeling of the junction, this enhancement is discussed in terms of both carbon nanotube (CNT) p-doping, induced by the interaction with the oxidizing molecules, and work function changes across the junction. Unlike studies so far reported, where the PCE enhancement was correlated only qualitatively to CNT doping, our study (i) provides a novel and reversible path to tune and considerably enhance the cell efficiency by a few ppm gas exposure, and (ii) shows computational results that quantitatively relate the observed effects to the electrostatics of the cell through a systematic calculation of the work function. These effects have been cross-checked by exposing the cell to reducing molecules (i.e·NH3) that resulted to be detrimental to the cell efficiency, consistently with the theoretical ab-initio calculations.
Collapse
Affiliation(s)
- Sonia Freddi
- Surface Science and Spectroscopy Lab @ I-Lamp, and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy; Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Simona Achilli
- Dipartimento di Fisica, Università di Milano, via Celoria 16, 20133 Milano, Italy
| | - Raffaella Soave
- Istituto di Scienze e Tecnologie Chimiche "Giulio Natta" SCITEC-CNR Via C. Golgi, 19- 20133 Milano, Italy
| | - Stefania Pagliara
- Surface Science and Spectroscopy Lab @ I-Lamp, and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
| | - Giovanni Drera
- Surface Science and Spectroscopy Lab @ I-Lamp, and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
| | - Andrea De Poli
- Surface Science and Spectroscopy Lab @ I-Lamp, and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
| | - Francesco De Nicola
- Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | | | - Paola Castrucci
- Dipartimento di Fisica, Università di Roma Tor Vergata, 00133 Roma, Italy
| | - Luigi Sangaletti
- Surface Science and Spectroscopy Lab @ I-Lamp, and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy.
| |
Collapse
|
2
|
Ponzoni S, Achilli S, Pintossi C, Drera G, Sangaletti L, Castrucci P, De Crescenzi M, Pagliara S. Hybridized C-O-Si Interface States at the Origin of Efficiency Improvement in CNT/Si Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2017; 9:16627-16634. [PMID: 28425281 DOI: 10.1021/acsami.7b01766] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Despite the astonishing values of the power conversion efficiency reached, in just less than a decade, by the carbon nanotube/silicon (CNT/Si) solar cells, many doubts remain on the underlying transport mechanisms across the CNT/Si heterojunction. Here, by combining transient optical spectroscopy in the femtosecond timescale, X-ray photoemission, and a systematic tracking of I-V curves across all phases of the interlayer SiOx growth at the interface, we grasp the mechanism that adequately preserves charge separation at the junction, hindering the photoexcited carrier recombination. Moreover, supported by ab initio calculations aimed to model the complex CNT-Si heterointerface, we show that oxygen-related states at the interface act as entrapping centers for the photoexcited electrons, thus preventing recombination with holes that can flow from Si to CNT across the SiOx layer.
Collapse
Affiliation(s)
- Stefano Ponzoni
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore , 25121 Brescia, Italy
| | - Simona Achilli
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore , 25121 Brescia, Italy
- CNR - National Research Council of Italy, ISTM , via Golgi 19, 20133 Milano, Italy
| | - Chiara Pintossi
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore , 25121 Brescia, Italy
| | - Giovanni Drera
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore , 25121 Brescia, Italy
| | - Luigi Sangaletti
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore , 25121 Brescia, Italy
| | - Paola Castrucci
- Dipartimento di Fisica, Università degli Studi di Roma Tor Vergata , via della Ricerca Scientifica 1, 00133 Roma, Italy
| | - Maurizio De Crescenzi
- Dipartimento di Fisica, Università degli Studi di Roma Tor Vergata , via della Ricerca Scientifica 1, 00133 Roma, Italy
| | - Stefania Pagliara
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore , 25121 Brescia, Italy
| |
Collapse
|
3
|
Rigoni F, Pintossi C, Drera G, Pagliara S, Lanti G, Castrucci P, De Crescenzi M, Sangaletti L. A cross-functional nanostructured platform based on carbon nanotube-Si hybrid junctions: where photon harvesting meets gas sensing. Sci Rep 2017; 7:44413. [PMID: 28294128 PMCID: PMC5353639 DOI: 10.1038/srep44413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 02/10/2017] [Indexed: 11/09/2022] Open
Abstract
A combination of the functionalities of carbon nanotube (CNT)-Si hybrid heterojunctions is presented as a novel method to steer the efficiency of the photovoltaic (PV) cell based on these junctions, and to increase the selectivity and sensitivity of the chemiresistor gas sensor operated with the p-doped CNT layer. The electrical characteristics of the junctions have been tracked by exposing the devices to oxidizing (NO2) and reducing (NH3) molecules. It is shown that when used as PV cells, the cell efficiency can be reversibly steered by gas adsorption, providing a tool to selectively dope the p-type layer through molecular adsorption. Tracking of the current-voltage curve upon gas exposure also allowed to use these cells as gas sensors with an enhanced sensitivity as compared to that provided by a readout of the electrical signal from the CNT layer alone. In turn, the chemiresistive response was improved, both in terms of selectivity and sensitivity, by operating the system under illumination, as the photo-induced charges at the junction increase the p-doping of CNTs making them more sensitive to NH3 and less to NO2.
Collapse
Affiliation(s)
- F. Rigoni
- Surface Science and Spectroscopy Lab @ I-Lamp and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
- CNR-INO and Sensor Lab, Dept. of Information Engineering, University of Brescia, Italy
| | - C. Pintossi
- Surface Science and Spectroscopy Lab @ I-Lamp and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
| | - G. Drera
- Surface Science and Spectroscopy Lab @ I-Lamp and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
| | - S. Pagliara
- Surface Science and Spectroscopy Lab @ I-Lamp and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
| | - G. Lanti
- Surface Science and Spectroscopy Lab @ I-Lamp and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
| | - P. Castrucci
- Dipartimento di Fisica, Università di Roma, Tor Vergata, Italy
| | - M. De Crescenzi
- Dipartimento di Fisica, Università di Roma, Tor Vergata, Italy
| | - L. Sangaletti
- Surface Science and Spectroscopy Lab @ I-Lamp and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy
| |
Collapse
|
4
|
Jia Y, Zhang Z, Xiao L, Lv R. Carbon Nanotube-Silicon Nanowire Heterojunction Solar Cells with Gas-Dependent Photovoltaic Performances and Their Application in Self-Powered NO2 Detecting. NANOSCALE RESEARCH LETTERS 2016; 11:299. [PMID: 27299654 PMCID: PMC4907969 DOI: 10.1186/s11671-016-1514-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/01/2016] [Indexed: 06/06/2023]
Abstract
A multifunctional device combining photovoltaic conversion and toxic gas sensitivity is reported. In this device, carbon nanotube (CNT) membranes are used to cover onto silicon nanowire (SiNW) arrays to form heterojunction. The porous structure and large specific surface area in the heterojunction structure are both benefits for gas adsorption. In virtue of these merits, gas doping is a feasible method to improve cell's performance and the device can also work as a self-powered gas sensor beyond a solar cell. It shows a significant improvement in cell efficiency (more than 200 times) after NO2 molecules doping (device working as a solar cell) and a fast, reversible response property for NO2 detection (device working as a gas sensor). Such multifunctional CNT-SiNW structure can be expected to open a new avenue for developing self-powered, efficient toxic gas-sensing devices in the future.
Collapse
Affiliation(s)
- Yi Jia
- Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing, 100094, China.
| | - Zexia Zhang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Lin Xiao
- Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing, 100094, China
| | - Ruitao Lv
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
| |
Collapse
|
5
|
Stolz BW, Tune DD, Flavel BS. The effect of dry shear aligning of nanotube thin films on the photovoltaic performance of carbon nanotube-silicon solar cells. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:1486-1491. [PMID: 27826524 PMCID: PMC5082438 DOI: 10.3762/bjnano.7.141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/07/2016] [Indexed: 06/06/2023]
Abstract
Recent results in the field of carbon nanotube-silicon solar cells have suggested that the best performance is obtained when the nanotube film provides good coverage of the silicon surface and when the nanotubes in the film are aligned parallel to the surface. The recently developed process of dry shear aligning - in which shear force is applied to the surface of carbon nanotube thin films in the dry state, has been shown to yield nanotube films that are very flat and in which the surface nanotubes are very well aligned in the direction of shear. It is thus reasonable to expect that nanotube films subjected to dry shear aligning should outperform otherwise identical films formed by other processes. In this work, the fabrication and characterisation of carbon nanotube-silicon solar cells using such films is reported, and the photovoltaic performance of devices produced with and without dry shear aligning is compared.
Collapse
Affiliation(s)
- Benedikt W Stolz
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
- Department of Physics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Daniel D Tune
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
- Centre for Nanoscale Science and Technology, The Flinders University of South Australia, Adelaide 5042, Australia
| | - Benjamin S Flavel
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
| |
Collapse
|