分子束外延(MBE)增长未掺杂GaAs/AlGaAs构成双异质的非辐射寿命的优化(DH)
Optimization of the Nonradiative Lifetime of Molecular-Beam-Epitaxy (MBE)-Grown Undoped GaAs/AlGaAs Double Heterostructures (DH)
关键词:铝镓砷化物;外延生长;量子效率;太阳能电池
摘 要:In this report, we present results of an ongoing study aimed at measuring and optimizing the nonradiative lifetime and the internal radiative quantum efficiency of molecular beam epitaxy (MBE)-grown gallium arsenide (GaAs) solar cells that are grown at the U.S. Army Research Laboratory (ARL) using different substrate growth temperatures and arsenic (As)/gallium (Ga) flux ratios to determine the growth parameters that maximize the bulk GaAs minority carrier nonradiative lifetime. We report a significant increase in the nonradiative lifetime and the internal radiative quantum efficiency of MBE- grown GaAs/aluminum gallium arsenide (AlGaAs) double heterostructure (DH) structures grown at ARL with a growth temperature of 595 C and an As/Ga flux ratio = 15. Our results show that the nonradiative lifetime and internal radiative quantum efficiency of the DH structures grown using these parameters are comparable to those of the highest quality reported MBE-grown GaAs.