Ellipsometry Characterisation for the Cd_1-xZn_xTe_1-ySe_y Semiconductor Used in X-ray and Gamma Radiation Detectors

Abstract

The study of the optical properties of the Cd1-xZnxTe1-ySey (CZTS) crystal provides a clear idea about its response to incident X-ray or gamma radiation. This is important for selecting a proper composition of CZTS to achieve superior quality and high-resolution X-ray and gamma radiation detectors at room temperature and reduce their production cost. This article’s novelty is in lowering the cost of the optical and compositional characterisation of CZTS using the ellipsometry technique. The most significant successes achieved are the composition ellipsometry model determination of CZTS based on the Effective Medium Approximation (EMA) substrate of the binary compound CdTe and ZnSe with an oxide layer of CdTe and the experimental verification that the bandgap moves to lower energies with the addition of Se.

Keywords

• crystal composition
• surface composition
• optical models
• characterisation
• alloys
• semiconducting II-VI materials