Survey of Electronic and Local Structural Properties of Cd1−xCoxSe1−yTe(S)y by XAFS

Abstract

As an extension of our previous studies of multi-component semiconductors doped with magnetic impurities, this paper gives a comprehensive insight into electronic and local structure of crystalline semiconductors Cd0.98Co0.02Se, Cd0.98Co0.02Se0.9S0.1, and Cd0.98Co0.02Se0.9Te0.1. Detailed characterization of Co and Se local environment and overall influence of Co and S(Te) (co)doping on the host crystal structure has been obtained by X-ray absorption fine structure (XAFS) technique and electronic structure calculations. Important structural information on bond lengths and disorder parameters were extracted from the extended region of the absorption spectra, while the relationships between electronic and local structures were determined from the characteristic features appearing in the near-edge spectral region. The influence of various structural defects on local electronic properties, charge transfer and atomic interactions has been studied by theoretical modeling of XAFS spectra and calculations of local density of electronic states. The obtained findings offer possible means for improvement and extension of the practical application of CdSe-based materials by adjusting the details of their electronic structure.