Title :
Properties of GaAs/InGaAs quantum well solar cells under low concentration ratios
Author :
Yang, Ming-Ju ; Yamaguchi, Masafumi
Author_Institution :
Toyota Technol. Inst., Nagoya, Japan
fDate :
29 Sep-3 Oct 1997
Abstract :
Multi-quantum well (MQW) GaAs/In0.19Ga0.81As solar cells have been measured under low concentration levels (1~4 suns). An efficiency of 22% has been obtained at a ratio of 4 suns as opposed to 18% under 1 sun AM1.5 conditions. We explain the results in terms of an enhancement in minority-carrier lifetime under concentration. Even when the concentration ratio is low, the high-injection regime can be achieved since the carrier concentration in the intrinsic layer is very low. The existence of a high concentration of defects in the base layer has been observed by the DLTS analysis. Enhancement of the minority-carrier lifetime under concentration is thought to be due to recombination probability saturation of recombination centers with high-injection of minority carriers
Keywords :
III-V semiconductors; carrier lifetime; deep level transient spectroscopy; electron-hole recombination; gallium arsenide; indium compounds; minority carriers; semiconductor quantum wells; solar cells; 22 percent; 4 suns; AM1.5 conditions; DLTS analysis; GaAs-In0.19Ga0.81As; GaAs/In0.19Ga0.81As solar cells; GaAs/InGaAs quantum well solar cells; carrier concentration; defects concentration; efficiency; high-injection regime; intrinsic layer; low concentration levels; low concentration ratios; minority carriers injection; minority-carrier lifetime enhancement; recombination centers; recombination probability saturation; Electrodes; Gallium arsenide; Indium gallium arsenide; Optical filters; Photovoltaic cells; Quantum well devices; Radiative recombination; Solar heating; Substrates; Temperature;
Conference_Titel :
Photovoltaic Specialists Conference, 1997., Conference Record of the Twenty-Sixth IEEE
Conference_Location :
Anaheim, CA
Print_ISBN :
0-7803-3767-0
DOI :
10.1109/PVSC.1997.654236
