Effects of applied electric fields on the optical properties of CdZnO quantum well structures

CdZnO/MgZnO QW structures with higher Cd quantity are found to have smaller optical gain because of the strain-induced piezoelectric polarization and the spontaneous polarization. These strain-induced polarizations can be reduced effectively by applied electric fields in CdZnO/ZnMgO QW structures with high Cd quantity. For optical properties of CdZnO/MgZnO QW structures, the optical gain is increased because the internal field is compensated with the reverse field, confirmed by Stark shifts. These results demonstrate that a high-performance optical-devices operation can be realized in CdZnO/MgZnO QW structures by eliminating the droop phenomenon.