Structural, electronical and thermoelectric properties of CdGa2S4 compound under high pressures by mBJ approach
The structural, electronic and thermoelectric properties of CdGa2S4 under pressure are studied by the modified Becke–Johnson (mBJ) approach and the Boltzmann transport theory. The calculated structural properties indicate that the optimized lattice constants decrease with increasing pressure. We found that the size of the band gap reached a maximum value and then it started to decrease with increasing pressure due to a band anticrossing at the Γ point. The results indicate that a high thermoelectric efficiency can be achieved if the size of band gap can be controlled under applying external pressure. For the n and p-type doping of CdGa2S4, the largest value of the anisotropic figure of merit is obtained for p-type doping. At 0.58 GPa, the best figure of merit of 1.04 is achieved along the z-direction at 800 K.
We thank Prof. Blaha of Vienna University of Technology, Austria and Prof. Madsen of Ruhr University in Bochum, Germany, for help in the use of Wien2k and BoltzTrap packages.
- 19.P. Blaha, K. Schwarz, G.K.H. Madsen, D. Kvasnicka, J. Luitz, Wien2k: An Augmented Plane Wave Plus Local Orbitals Program for Calculating Crystal Properties. (Vienna University of Technology, Austria, 2001)Google Scholar
- 30.A.N. Georgobiani, S.I. Radautsan, M. Tiginyanu, Sov. Phys. Semicond. 19, 121 (1985)Google Scholar
- 31.M.F. Cabrera, J. Phys. 13, 10117–10124 (2001)Google Scholar