First principle optoelectronic studies of visible light sensitive CZT

• First principle calculations using mBJ are carried out for Cd1-xZnxTe (0 ⩽ x ⩽ 1).
• The calculated band gaps are in agreement with experiments.
• The band gap nature is direct and increases with Zn concentration.
• The material is optically active, therefore the optical properties are also investigated.

The most attractive optical material in solar cells applications, CdZnTe (CZT), has been extensively studied both, experimentally and theoretically. The results obtained by various theoretical models are way too far from the experiments and hence, they fail to demonstrate the true theoretical picture of the compound. In the present study the electronic band gap, band gap bowing and optical properties of Cd1−xZnxTe (0 ⩽ x ⩽ 1) are revisited with an effective theoretical model to provide accurate theoretical foundations to the experimental results. The calculations are performed with the full potential linearized augmented plane wave (FPLAPW) method with the generalized gradient approximation + modified Becke–Johnson (GGAmBJ) potential. The calculated results are in agreement with the experimental results. The band gap increases non-lineally with the concentration. The optical properties of the compound like absorption coefficient, refractive index, reflectivity, energy loss function and oscillator strength are also calculated. The number of effective electrons in optical excitations decreases with the increase in concentration of Zn.

Figure optionsDownload as PowerPoint slide