Electrical and Photo-luminescence Properties of ZnSe Thin Films Grown by Molecular Beam Epitaxy: Substrate Temperature Effect

Abstract
The substrate temperature effect on electrical and PL properties of undoped MBE ZnSe has been investigated. Resistivity (ρ) of the epilayers shows an abrupt change with the substrate temperature (T s): ρ∼106 ohm-cm for T s∼250°C or \gtrsim400°C, while ρ∼1 ohm-cm for 280°C\lesssimT s\lesssim370°C. The substrate temperature dependence of PL spectra of the epilayers reveals that (1) the high resistivity is caused by the increase of the SA centers above 400°C and below 250°C, and (2) the diffusion of As and Ga from the GaAs substrate occurs during the growth process.