Theoretical Investigations of Quaternary Semiconductors CsInCdTe3 (Ln = La, Pr, Nd and Sm)

Structural, electronic, optical and thermoelectric properties of quaternary semiconductor materials CsLnCdTe3 (Ln = La, Pr, Nd and Sm) are investigated using density functional theory. Structural parameters such as lattice constants, bulk modulii and bond lengths are found to be consistent with experimental data. The calculated electronic energy band gaps of CsLaCdTe3, CsPrCdTe3, CsNdCdTe3 and CsSmCdTe3 are 1.55 eV, 1.12 eV, 1.23 eV and 1.08 eV. Band gap energies of these compounds exhibit an obvious redshift compared to the base material CdTe (1.59 eV). The optical parameters reveal that these compounds are good dielectric materials. The Seebeck effect, electrical and thermal conductivities and power factor reveal that these compounds are p-type semiconductors.