Minority carrier lifetimes in molecular beam epitaxy grown Al[sub [ital x]]Ga[sub 1[minus][ital x]]As/GaAs double heterostructures doped with aluminum

Journal Article · Thu Jul 01 00:00:00 EDT 1993 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578805· OSTI ID:6237416

Sheldon, P; Keyes, B M; Ahrenkiel, R K; Asher, S E ^[1]

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1. National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

Both Al-treated [ital p]BN crucibles and Al-doped Ga melts have been used to reduce Ga-cell related oval defect densities in molecular beam epitaxy (MBE) grown epilayers. This practice, although effective in reducing the oval defect density, results in small amounts of Al contamination in the grown films. In this work, we have grown diagnostic Al[sub 0.3]Ga[sub 0.7]As/GaAs double heterostructure (DH) devices doped with Al in order to determine the effect of Al contamination on the minority-carrier lifetime. The active region of the DH structures was doped with Al at 5[times]10[sup 18] atoms/cm[sup 3] to emulate the levels observed when Al-treated [ital p]BN crucibles are used. Al impurity levels and distribution profiles were characterized by secondary ion mass spectrometry, and minority-carrier lifetimes of DH devices were characterized using time-resolved photoluminescence (PL) measurements. Device structures grown with various GaAs active layer thicknesses were used to calculate the interface recombination velocity ([ital S]) and the bulk lifetime ([tau][sub [ital B]]). We found that Al doping of the GaAs active layer adversely affects the measured PL decay time. GaAs active layers of DH devices doped with Al exhibited poor bulk lifetimes ([tau][sub [ital B]][le]120 ns) limited by Shockley--Read--Hall recombination. In contrast, DH devices grown with Al-free active layers resulted in significantly improved PL decay times with bulk lifetimes as high as [tau][sub [ital B]]=700 ns.

• DOE Contract Number: AC02-83CH10093
• OSTI ID: 6237416
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Vol. 11:4; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ARSENIDES
CARRIER LIFETIME
GALLIUM ARSENIDES
ALUMINIUM ADDITIONS
HETEROJUNCTIONS
MOLECULAR BEAM EPITAXY
PHOTOLUMINESCENCE
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
EPITAXY
GALLIUM COMPOUNDS
JUNCTIONS
LIFETIME
LUMINESCENCE
PNICTIDES
SEMICONDUCTOR JUNCTIONS
360606* - Other Materials- Physical Properties- (1992-)