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Criteria for improving the properties of ZnGeAs 2 solar cells
Author(s) -
Peshek Timothy J.,
Zhang Lei,
Singh Rakesh K.,
Tang ZhiZhong,
Vahidi Mahmoud,
To Bobby,
Coutts Timothy J.,
Gessert Timothy A.,
Newman Nathan,
Schilfgaarde Mark
Publication year - 2013
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/pip.2177
Subject(s) - borosilicate glass , materials science , amorphous solid , optoelectronics , crystallization , substrate (aquarium) , open circuit voltage , solar cell , semiconductor , layer (electronics) , deposition (geology) , thermal , chemical engineering , nanotechnology , voltage , composite material , chemistry , electrical engineering , crystallography , paleontology , oceanography , physics , sediment , meteorology , engineering , biology , geology
ABSTRACT We explore the potential utility of the II‐IV‐V semiconductor ZnGeAs 2 as the absorber material in solar cells. As‐deposited ZnGeAs 2 films prepared by pulsed laser deposition are amorphous because of the limited substrate temperature that can be used without the rapid loss of volatile Zn and As. Thermal processing above 450 °C results in crystallization and improved electrical properties with hole mobilities as high as 58 cm 2 /V s. The annealed films were used to fabricate p ‐type ZnGeAs 2 : n ‐type CdS cells on SnO 2 ‐buffered borosilicate glass substrates in the so‐called superstrate geometry. Light‐induced currents of up to ~2 mA/cm 2 and open‐circuit voltages of up to 470 mV were observed using backside illumination, indicating that these nascent devices hold potential for realizing high performance solar cells from earth‐abundant elements. The performance of the devices fabricated to‐date is degraded by conduction through shorts resulting from the presence of micron‐sized pinholes in the absorber layer. Copyright © 2012 John Wiley & Sons, Ltd.