Title: Effect of Na and Ti-doping on photovoltaic properties of CuInS₂ solar cells

Authors: Duy-Cuong Nguyen; Toshihiro Ryo; Laurent Lombez; Seigo Ito

Addresses: Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Shosha 2167, Himeji, Hyogo, 671-2280, Japan ' Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Shosha 2167, Himeji, Hyogo, 671-2280, Japan ' Institut de Recherche et Développement sur l'Energie Photovoltaïque (IRDEP), UMR 7174 - CNRS-EDF-Chimie ParisTech, EDF R&D, 6 quai Watier, 78401 Chatou Cedex, France ' Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Shosha 2167, Himeji, Hyogo, 671-2280, Japan

Abstract: CuInS₂ (CIS) films were deposited on In₂S₃/TiO₂/FTO/glass under air by spray pyrolysis, resulting in superstrate-structured solar cells. We found a significant difference of images between scanning electron microscope and optical microscope, which suggests crystallisation of spray-pyrolysis CIS particles in In₂S₃ layer. The In₂S₃ covering layer was confirmed by Auger Electron spectroscopy. Titanium-doping in In₂S₃ improved fill factor of CIS cells, however, the conversion efficiency was not changed. The best cells were achieved at 4% sodium doping using 350°C hot-plate and their cell parameters are open-circuit voltage = 0.551 V, photocurrent density = 11.65 mA/cm², fill factor = 0.45, and a conversion efficiency = 2.88%.

Keywords: solar cells; copper indium sulphide; CIS films; spray pyrolysis; sodium doping; titanium doping.

DOI: 10.1504/IJNT.2013.053141

International Journal of Nanotechnology, 2013 Vol.10 No.3/4, pp.279 - 287

Published online: 05 Apr 2013 *

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