Interfacial recombination at (AlGa)As/GaAs heterojunction structures

Abstract

A determination has been made of the effective interfacial recombination at Al0.25Ga0.75As/GaAs and Al0.5Ga0.5As/GaAs heterojunctions. The recombination velocity was deduced from the dependence of the minority-carrier lifetime on junction spacing in heterojunction diodes. For heterojunction spacings in excess of about 1 μm, the interfacial recombination can be characterized by a recombination velocity of 4×103 and 8×103 cm/s for Al0.25Ga0.75As/GaAs and Al0.5Ga0.5As/GaAs heterojunctions, respectively. However, for double-heterojunction spacings below 1 μm, the minority-carrier lifetime is invariant, suggesting that the interfacial recombination velocity decreases with decreasing heterojunction spacing. No such effect is observed in single-heterojunction diodes.