We discuss the electric-field dependence of the optical absorption for a particular type of quantum well structures, in which one or more small wells are embedded in a big well. In such structures, local energy states confined by the small well(s) and global states confined by the big well have different electric field dependence while their wave functions remain overlapped. Thus, a large Stark effect (large energy shift and oscillator strength) can be achieved for the optical transition from a local state to a global state. This concept of using the local and global states can be applied to both interband and intersubband transitions. For intersubband transitions, a typical 10-20 meV shift is predicted, compared to a reported 1.1 meV blue shift at the field 30 kV/cm. For interband transitions, the Stark shift is also larger than that in the single quantum wells.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering