Growth and characterization of ZnSeGaAs single quantum well structures

The integration of II–VI and III–V semiconductors into a single II–VI/III–V heterojunction device enables the exploitation of the many similarities, as well as the many differences, in material properties (energy bandgap, lattice constant, dielectric constant, etc.) to create new devices exhibiting unique optical and electronic properties. The epitaxial growth of dielectric quantum wells (QWs) composed of ZnSe and GaAs is under investigation. One of the critical factors affecting the properties of the ZnSeGaAs QW structure is the formation of the heterovalent interfaces, particularly the formation of the inverted interface formed by GaAs nucleated onto a ZnSe epitaxial surface. The stoichiometry of each interface is engineered by using various growth techniques. Due to the severe mismatch in optimal growth temperatures for the two material systems (600°C for GaAs and 300°C for ZnSe), additional emphasis has been placed on the reduced temperature growth of GaAs on ZnSe. The effects of the growth parameters and nucleation methodology are examined by in situ surface reconstruction analysis using reflection high energy electron diffraction and ex situ using transmission electron microscopy. The optical properties of the reduced temperature GaAs and ZnSeGaAs QWs are further investigated with photoluminescence.