Title :
Evidence for enhanced carrier escape from multiple stepped quantum well (MSQW) and its impact on photovoltaic performance
Author :
Wen, Yu ; Wang, Yunpeng ; Sugiyama, Masakazu ; Nakano, Yoshiaki
Author_Institution :
Res. Center for Adv. Sci. & Technol., Univ. of Tokyo, Tokyo, Japan
Abstract :
A multiple stepped quantum wells (MSQWs) solar cell, in which GaAs stepped-potential layers are sandwiched between strain-balanced InGaAs wells and GaAsP barriers, has been proposed. The bias-dependent photoluminescence has been studied to estimate the radiative recombination velocity, in comparison between the MSQW and the normal multiple quantum well (MQW) structures. Thermalized energy distribution from the wells was examined in terms of temperature-dependent PL and higher average carrier temperature was observed for MSQWs than for MQWs. Such enhanced carrier escape in the case of MSQWs allowed us to obtain increased short-circuit current density 25 mA/cm2 which is approximately 14% higher than that of a normal MQWs solar cell.
Keywords :
III-V semiconductors; current density; electron-hole recombination; gallium arsenide; indium compounds; photoluminescence; quantum well devices; sandwich structures; semiconductor quantum wells; solar cells; GaAs stepped-potential layers; GaAsP barriers; InGaAs-GaAs-GaAsP; average carrier temperature; bias-dependent photoluminescence; enhanced carrier escape; multiple stepped quantum well solar cell; normal multiple quantum well structures; photovoltaic performance; radiative recombination velocity; short-circuit current density; strain-balanced InGaAs wells; temperature-dependent PL; thermalized energy distribution; Charge carrier processes; Gallium arsenide; Photovoltaic cells; Quantum dots; Quantum mechanics; Quantum well devices; Temperature measurement;
Conference_Titel :
Compound Semiconductor Week (CSW/IPRM), 2011 and 23rd International Conference on Indium Phosphide and Related Materials
Conference_Location :
Berlin
Print_ISBN :
978-1-4577-1753-6
Electronic_ISBN :
978-3-8007-3356-9
