title: Dependence of the minority-carrier lifetime on the stoichiometry of CdTe using time-resolved photoluminescence and first-principles calculations.
abstract: CdTe is one of the most promising materials for thin-film solar cells. However, further improvement of its performance is hindered by its relatively short minority-carrier lifetime. Combining theoretical calculations and experimental measurements, we find that for both intrinsic CdTe and CdTe solar cell devices, longer minority-carrier lifetimes can be achieved under Cd-rich conditions, in contrast to the previous belief that Te-rich conditions are more beneficial. First-principles calculations suggest that the dominant recombination centers limiting the minority-carrier lifetime are the Te antisite and Te interstitial. Therefore, we propose that to optimize the solar cell performance, extrinsic p-type doping (e.g., N, P, or As substitution on Te sites) in CdTe under Cd-rich conditions should be a good approach to simultaneously increase both the minority-carrier lifetime and hole concentration.
authors: National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
authors: Jie
authors: J
authors: Ma
authors: Darius
authors: D
authors: Kuciauskas
authors: David
authors: D
authors: Albin
authors: Raghu
authors: R
authors: Bhattacharya
authors: Matthew
authors: M
authors: Reese
authors: Teresa
authors: T
authors: Barnes
authors: Jian V
authors: JV
authors: Li
authors: Timothy
authors: T
authors: Gessert
authors: Su-Huai
authors: SH
authors: Wei