Interband Stark effects in In xGa 1−xAs/In yAl 1−yAs coupled step quantum wells

Abstract

The effects of an electric field on the interband transitions in In x Ga 1− x As/In y Al 1− y As coupled step quantum wells have been investigated both experimentally and theoretically. A In x Ga 1− x As/In y Al 1− y As coupled step quantum well sample consisted of the two sets of a 50 Å In 0.53Ga 0.47As shallow quantum well and a 50 Å In 0.65Ga 0.35As deep step quantum well bounded by two thick In 0.52Al 0.48As barriers separated by a 30 Å In 0.52Al 0.48As embedded potential barrier. The Stark shift of the interband transition energy in the In x Ga 1− x As/In y Al 1− y As coupled step quantum well is larger than that of the single quantum well, and the oscillator strength in the In x Ga 1− x As/In y Al 1− y As coupled step quantum well is larger than that in a coupled rectangular quantum well. These results indicate that In x Ga 1− x As/In y Al 1− y As coupled step quantum wells hold promise for potential applications in optoelectron devices, such as tunable lasers.