Photoelectrical and Optical Properties of II-VI Compound Semiconductor Surfaces and Their Interfaces

Abstract

Optical and photoelectrical properties of surface states of CdTe and ZnO, as well as their interfaces with electrolyte and chemisorbed oxygen were investigated. For that reason photoluminescence (PL), reflectance, electroreflectance (ER) and photocurrent spectra of CdTe, CdTe-chemisorbed oxygen, CdTe- and ZnO-electrolyte interfaces depending on temperature, concentration of charge carriers, light polarization, chemisorption and value of surface potential (SP) were experimentally investigated. Quasi-two-dimensional surface excitons (quasi-2DSE) and size-quantized quasi-2DSE were observed. A model of size-quantized quasi-2DSE associated with two-dimensional surface subbands (2DSS) was suggested. The behaviour of such excitons and the parameters of quantum inverse layer were determined. The binding energy of quasi-2DSE was evaluated.