Optical properties of circular polarization of ZnSe/ZnTe Quantum dots/ZnSe type II semiconductor heterostructures

Spin polarization of light emission arising from self-assembled ZnTe/ZnSe quantum dots grown by molecular beam epitaxy is investigated. It is found that the magnitude and sign of the degree of spin polarization can be drastically
manipulated by excitation wavelength. The underlying mechanisms can be explained well based on the combination of band alignment, energy level splitting, as well as selection rule of optical transitions. The unique tunability of spin polarization of light emission by excitation wavelength adds an unprecedented feature to semiconductor materials, which have been studies for quite a long time. It is believed that the results obtained in this study will pave a key step for the development of optospintronics.