Normal incidence infra-red absorption from intersub-band transitions in <i>p</i> -type GaInAs/AIInAs quantum wells

Abstract

Infra-red intersub-band absorption measurements were performed on p-type Ga0.47In0.53As/Al0.48In0.52As multiquantum wells using normally incident radiation. Several strong intersub-band absorption peaks were observed in the wavelength range 6–12 μm. The transition from the impurity bound state to the extended state was observed for the first time.