Electric field dependent intersubband optical transitions in a ZnCdSe–ZnSe superlattice

Abstract

The polarization dependence of the excitonic transition in ZnSe-Zn0.8Cd0.2Se superlattices was studied by low-field electroreflection spectroscopy. A new peak observed in the lower energy side of the n=2 heavy-hole exciton E2hh at room temperature is attributed to the forbidden transition in zero field from the n=2 heavy-hole state to the n=1 electron state. This reflection change is found to be polarization dependent.

Excitonic effects can lead to decreased intersubband oscillator strength

“…This is not surprising, and we expect excitonic effects to be pronounced in many materials of contemporary interest such as in III-V semiconductors such as GaN and II-VI semiconductors such as ZnSe. 10 What is surprising is the sign of the result. We show that the excitonic transition can exhibit reduced oscillator strength in comparison to a transition of the same energy with no excitonic effects.…”