Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells
Abstract
Carrier recombination at the metal-semiconductor contacts has become a significant obstacle to the further advancement of high-efficiency diffused-junction silicon solar cells. This paper provides the proof-of-concept of a procedure to reduce contact recombination by means of enhanced metal-insulator-semiconductor (MIS) structures. Lightly diffused n{sup +} and p{sup +} surfaces are passivated with SiO{sub 2}/a-Si:H and Al{sub 2}O{sub 3}/a-Si:H stacks, respectively, before the MIS contacts are formed by a thermally activated alloying process between the a-Si:H layer and an overlying aluminum film. Transmission/scanning transmission electron microscopy (TEM/STEM) and energy dispersive x-ray spectroscopy are used to ascertain the nature of the alloy. Idealized solar cell simulations reveal that MIS(n{sup +}) contacts, with SiO{sub 2} thicknesses of ∼1.55 nm, achieve the best carrier-selectivity producing a contact resistivity ρ{sub c} of ∼3 mΩ cm{sup 2} and a recombination current density J{sub 0c} of ∼40 fA/cm{sup 2}. These characteristics are shown to be stable at temperatures up to 350 °C. The MIS(p{sup +}) contacts fail to achieve equivalent results both in terms of thermal stability and contact characteristics but may still offer advantages over directly metallized contacts in terms of manufacturing simplicity.
- Authors:
-
- Research School of Engineering, The Australian National University, Canberra, ACT 0200 (Australia)
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Micro Engineering (IMT), Photovoltaics and Thin Film Electronic Laboratory PVLab, Maladière 71b, CH-200 Neuchâtel (Switzerland)
- Publication Date:
- OSTI Identifier:
- 22308156
- Resource Type:
- Journal Article
- Journal Name:
- Journal of Applied Physics
- Additional Journal Information:
- Journal Volume: 116; Journal Issue: 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALLOYS; ALUMINIUM OXIDES; AMORPHOUS STATE; CURRENT DENSITY; FILMS; HYDROGENATION; LAYERS; MIS SOLAR CELLS; RECOMBINATION; SEMICONDUCTOR JUNCTIONS; SEMICONDUCTOR MATERIALS; SILICON; SILICON OXIDES; SILICON SOLAR CELLS; SIMULATION; SURFACES; TRANSMISSION; TRANSMISSION ELECTRON MICROSCOPY; X-RAY SPECTROSCOPY
Citation Formats
Bullock, J., E-mail: james.bullock@anu.edu.au, Cuevas, A., Yan, D., Demaurex, B., Hessler-Wyser, A., and De Wolf, S. Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells. United States: N. p., 2014.
Web. doi:10.1063/1.4900539.
Bullock, J., E-mail: james.bullock@anu.edu.au, Cuevas, A., Yan, D., Demaurex, B., Hessler-Wyser, A., & De Wolf, S. Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells. United States. https://doi.org/10.1063/1.4900539
Bullock, J., E-mail: james.bullock@anu.edu.au, Cuevas, A., Yan, D., Demaurex, B., Hessler-Wyser, A., and De Wolf, S. 2014.
"Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells". United States. https://doi.org/10.1063/1.4900539.
@article{osti_22308156,
title = {Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells},
author = {Bullock, J., E-mail: james.bullock@anu.edu.au and Cuevas, A. and Yan, D. and Demaurex, B. and Hessler-Wyser, A. and De Wolf, S.},
abstractNote = {Carrier recombination at the metal-semiconductor contacts has become a significant obstacle to the further advancement of high-efficiency diffused-junction silicon solar cells. This paper provides the proof-of-concept of a procedure to reduce contact recombination by means of enhanced metal-insulator-semiconductor (MIS) structures. Lightly diffused n{sup +} and p{sup +} surfaces are passivated with SiO{sub 2}/a-Si:H and Al{sub 2}O{sub 3}/a-Si:H stacks, respectively, before the MIS contacts are formed by a thermally activated alloying process between the a-Si:H layer and an overlying aluminum film. Transmission/scanning transmission electron microscopy (TEM/STEM) and energy dispersive x-ray spectroscopy are used to ascertain the nature of the alloy. Idealized solar cell simulations reveal that MIS(n{sup +}) contacts, with SiO{sub 2} thicknesses of ∼1.55 nm, achieve the best carrier-selectivity producing a contact resistivity ρ{sub c} of ∼3 mΩ cm{sup 2} and a recombination current density J{sub 0c} of ∼40 fA/cm{sup 2}. These characteristics are shown to be stable at temperatures up to 350 °C. The MIS(p{sup +}) contacts fail to achieve equivalent results both in terms of thermal stability and contact characteristics but may still offer advantages over directly metallized contacts in terms of manufacturing simplicity.},
doi = {10.1063/1.4900539},
url = {https://www.osti.gov/biblio/22308156},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 16,
volume = 116,
place = {United States},
year = {Tue Oct 28 00:00:00 EDT 2014},
month = {Tue Oct 28 00:00:00 EDT 2014}
}