Title :
Formation Of ZnTe: Cu/Ti Contacts at High Temperature for CdS/CdTe Devices
Author :
Gessert, T.A. ; Asher, S. ; Johnston, S. ; Duda, A. ; Young, M.R. ; Moriarty, T.
Author_Institution :
NREL, Golden, CO
Abstract :
We study the performance of CdS/CdTe thin-film devices contacted with ZnTe:Cu/Ti of various thickness at a higher-than-optimum temperature of ~360degC. At this temperature, optimum device performance requires the same thickness of ZnTe:Cu as for similar contacts formed at a lower temperature of 320degC. C-V analysis indicates that a ZnTe:Cu layer thickness of <~0.5 mum does not yield the degree of CdTe net acceptor concentration necessary to reduce space charge width to its optimum value for n-p device operation. The thickest ZnTe:Cu layer investigated (1mum) yields the highest CdTe net acceptor concentration, lowest value of Jo, and highest Voc. However, performance is limited for this device by poor fill factor. We suggest poor fill factor is due to Cu-related acceptors compensating donors in CdS
Keywords :
II-VI semiconductors; cadmium compounds; copper; high-temperature effects; photoelectric devices; thin film devices; titanium; zinc compounds; 320 C; 360 C; C-V analysis; CdS-CdTe; Cu-related acceptor compensating donors; ZnTe:Cu-Ti; acceptor concentration; fill factor; high temperature effect; n-p device operation; optimum device performance; photoelectric devices; photovoltaic devices; semiconductor contacts; semiconductor thin-film devices; space charge width; Capacitance-voltage characteristics; Metallization; Photovoltaic systems; Solar power generation; Space charge; Temperature control; Thickness control; Thin film devices; Voltage; Zinc compounds;
Conference_Titel :
Photovoltaic Energy Conversion, Conference Record of the 2006 IEEE 4th World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
1-4244-0017-1
Electronic_ISBN :
1-4244-0017-1
DOI :
10.1109/WCPEC.2006.279482
