skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Light-induced V{sub oc} increase and decrease in high-efficiency amorphous silicon solar cells

Abstract

High-efficiency amorphous silicon (a-Si:H) solar cells were deposited with different thicknesses of the p-type amorphous silicon carbide layer on substrates of varying roughness. We observed a light-induced open-circuit voltage (V{sub oc}) increase upon light soaking for thin p-layers, but a decrease for thick p-layers. Further, the V{sub oc} increase is enhanced with increasing substrate roughness. After correction of the p-layer thickness for the increased surface area of rough substrates, we can exclude varying the effective p-layer thickness as the cause of the substrate roughness dependence. Instead, we explain the observations by an increase of the dangling-bond density in both the p-layer—causing a V{sub oc} increase—and in the intrinsic absorber layer, causing a V{sub oc} decrease. We present a mechanism for the light-induced increase and decrease, justified by the investigation of light-induced changes of the p-layer and supported by Advanced Semiconductor Analysis simulation. We conclude that a shift of the electron quasi-Fermi level towards the conduction band is the reason for the observed V{sub oc} enhancements, and poor amorphous silicon quality on rough substrates enhances this effect.

Authors:
; ; ; ;  [1]
  1. Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin-Film Electronics Laboratory, Rue de la Maladière 71, CH-2000 Neuchâtel (Switzerland)
Publication Date:
OSTI Identifier:
22314407
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 116; Journal Issue: 9; 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:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; EFFICIENCY; FERMI LEVEL; LAYERS; ROUGHNESS; SEMICONDUCTOR MATERIALS; SILICON; SILICON CARBIDES; SILICON SOLAR CELLS; SIMULATION; SUBSTRATES; SURFACE AREA; THICKNESS; VISIBLE RADIATION

Citation Formats

Stuckelberger, M., E-mail: michael.stuckelberger@epfl.ch, Riesen, Y., Despeisse, M., Schüttauf, J. -W., Haug, F. -J., and Ballif, C. Light-induced V{sub oc} increase and decrease in high-efficiency amorphous silicon solar cells. United States: N. p., 2014. Web. doi:10.1063/1.4894457.
Stuckelberger, M., E-mail: michael.stuckelberger@epfl.ch, Riesen, Y., Despeisse, M., Schüttauf, J. -W., Haug, F. -J., & Ballif, C. Light-induced V{sub oc} increase and decrease in high-efficiency amorphous silicon solar cells. United States. https://doi.org/10.1063/1.4894457
Stuckelberger, M., E-mail: michael.stuckelberger@epfl.ch, Riesen, Y., Despeisse, M., Schüttauf, J. -W., Haug, F. -J., and Ballif, C. 2014. "Light-induced V{sub oc} increase and decrease in high-efficiency amorphous silicon solar cells". United States. https://doi.org/10.1063/1.4894457.
@article{osti_22314407,
title = {Light-induced V{sub oc} increase and decrease in high-efficiency amorphous silicon solar cells},
author = {Stuckelberger, M., E-mail: michael.stuckelberger@epfl.ch and Riesen, Y. and Despeisse, M. and Schüttauf, J. -W. and Haug, F. -J. and Ballif, C.},
abstractNote = {High-efficiency amorphous silicon (a-Si:H) solar cells were deposited with different thicknesses of the p-type amorphous silicon carbide layer on substrates of varying roughness. We observed a light-induced open-circuit voltage (V{sub oc}) increase upon light soaking for thin p-layers, but a decrease for thick p-layers. Further, the V{sub oc} increase is enhanced with increasing substrate roughness. After correction of the p-layer thickness for the increased surface area of rough substrates, we can exclude varying the effective p-layer thickness as the cause of the substrate roughness dependence. Instead, we explain the observations by an increase of the dangling-bond density in both the p-layer—causing a V{sub oc} increase—and in the intrinsic absorber layer, causing a V{sub oc} decrease. We present a mechanism for the light-induced increase and decrease, justified by the investigation of light-induced changes of the p-layer and supported by Advanced Semiconductor Analysis simulation. We conclude that a shift of the electron quasi-Fermi level towards the conduction band is the reason for the observed V{sub oc} enhancements, and poor amorphous silicon quality on rough substrates enhances this effect.},
doi = {10.1063/1.4894457},
url = {https://www.osti.gov/biblio/22314407}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 9,
volume = 116,
place = {United States},
year = {Sun Sep 07 00:00:00 EDT 2014},
month = {Sun Sep 07 00:00:00 EDT 2014}
}