DocumentCode :
1868382
Title :
High efficiency Cu2ZnSn(SxSe1−x)4 thin film solar cells by thermal co-evaporation
Author :
Shin, Byungha ; Wang, Kejia ; Gunawan, Oki ; Reuter, Kathleen B. ; Chey, S. Jay ; Bojarczuk, Nestor A. ; Todorov, Teodor ; Mitzi, David B. ; Guha, Supratik
Author_Institution :
IBM T.J. Watson Res. Center, Yorktown Heights, NY, USA
fYear :
2011
fDate :
19-24 June 2011
Abstract :
We report on the device results of thermally evaporated high efficiency Cu2ZnSn(SxSe1-x)4 (CZTSSe) thin film solar cells with power conversion efficiencies of 7.1% (x=1.0) and 7.5% (x=0.34). We have carried out extensive electrical and structural characterization of CZTSSe solar cells to identify major factors that limit the efficiency. Bias-dependent quantum efficiency measurements revealed ineffective collection of charge carriers photo-generated deep in the absorber layer suggesting a short minority carrier diffusion length, which was confirmed by time-resolved photoluminescence measurements. Temperature-dependence of the series resistance of the devices is consistent with the presence of a Schottky-type barrier in the back contact, likely caused by secondary phases near the CZTS/Mo interface and/or an interfacial MoSx layer.
Keywords :
Schottky barriers; carrier lifetime; copper compounds; molybdenum compounds; photoluminescence; semiconductor thin films; solar cells; tin compounds; vacuum deposition; zinc compounds; Cu2ZnSn(SSe)4; MoS; Schottky type barrier; absorber; back contact; bias dependent quantum efficiency measurements; charge carriers photogeneration; minority carrier diffusion length; power conversion efficiency; thermal co-evaporation; thin film solar cells; time-resolved photoluminescence measurements; Electric variables measurement; Films; Photonic band gap; Photovoltaic cells; Scanning electron microscopy; Temperature measurement; Wavelength measurement;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2011 37th IEEE
Conference_Location :
Seattle, WA
ISSN :
0160-8371
Print_ISBN :
978-1-4244-9966-3
Type :
conf
DOI :
10.1109/PVSC.2011.6186456
Filename :
6186456
Link To Document :
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