Title :
The effects of trap-induced lifetime variations on the design and performance of high-efficiency GaAs solar cells
Author :
Ringel, Steven A. ; Rohatgi, Ajeet
Author_Institution :
Dept. of Electr. Eng., Georgia Inst. of Technol., Atlanta, GA, USA
fDate :
11/1/1991 12:00:00 AM
Abstract :
The authors investigate the impact of Shockley-Read-Hall (SRH) lifetime behavior directly on GaAs solar cell performance and design optimization for various lifetime-limiting defects, characterized by trap position, cross section, and trap density. It is demonstrated theoretically and experimentally, for a specific cell design, how far GaAs cell efficiency can be from the optimum efficiency if certain types of bulk defects limit the lifetime and are not properly accounted for. A realistic situation is considered where cell designers/manufacturers know the bulk lifetime at some nominal carrier concentrations but are unaware of the trap characteristics or defect responsible for this lifetime. An improved GaAs p/n heteroface cell design is proposed. This design utilizes a high-low junction and a thin base, with AlGaAs back-surface passivation
Keywords :
III-V semiconductors; aluminium compounds; carrier lifetime; deep levels; gallium arsenide; minority carriers; solar cells; AlGaAs back-surface passivation; AlGaAs-GaAs solar cell; Shockley Read Hall lifetime; cell efficiency; deep levels; design optimization; high-low junction; minority carrier lifetime; p/n heteroface cell design; trap cross section; trap density; trap position; trap-induced lifetime variations; Degradation; Doping; Gallium arsenide; Laboratories; Manufacturing; Optoelectronic devices; Passivation; Photovoltaic cells; Semiconductor process modeling; Sun;
Journal_Title :
Electron Devices, IEEE Transactions on
