CuGaSe2 thin films prepared by a novel CCSVT technique for photovoltaic application

• Published in: Thin solid films Vol. 451-452; no. Complete; pp. 556 - 561
• Main Authors: Rusu, M., Wiesner, S., Fuertes Marrón, D., Meeder, A., Doka, S., Bohne, W., Lindner, S., Schedel-Niedrig, Th, Giesen, Ch, Heuken, M., Lux-Steiner, M.Ch
• Format: Journal Article
• Language: English
• Published: 22.03.2004
• ISSN: 0040-6090
• DOI: 10.1016/j.tsf.2003.10.089

A novel chemical close-spaced vapor transport (CCSVT) technique has been developed for the growth of the CuGaSe2 (CGSe) thin films on areas as large as 10x10 cm2. Cu precursors deposited on clean and Mo-coated soda lime glass substrates are thermally and chemically treated under gaseous GaClx/H2Se atmosphere in the CCSVT cell. The Ga2Se3 employed as source material is stoichiometrically volatilised at 550 DGC by a controlled amount of HCl/H2 agent. Single phase CGSe thin films are prepared with a growth rate of 230-240 nm/min by using a single stage process. A two-stage process is applied for the fine tuning of the CGSe composition and electronic properties appropriate for the subsequent solar cell preparation. Film characterisation including X-ray diffraction measurements, scanning electron microscopy observations, X-ray fluorescence analysis and elastic recoil detection analysis has been carried out. An 8.7% active area efficient ZnO/CdS/CuCaSe2 solar cell under AM1.5 conditions has been achieved.