Ab-initio investigation of optoelectronic and thermoelectric properties in new p-type Rattling Heuslers Sr2PtX (X=Xe and Te)

Abstract The structural, optoelectronic, and thermoelectric properties of the cubic Rattling Heusler compounds Sr2PtX (where X = Se, Te) are evaluated using the FP-LAPW method based on DFT within modified Becke-Johnson potential functional. The BoltzTraP code is used to calculate the thermoelectric properties. PBE-GGA calculations show that Sr2PtSe and Sr2PtTe are semiconductors with indirect band gaps estimated at 0.96 and 0.81 eV, respectively, while corresponding TB-mBJ calculated values are 1.45 and 1.33 eV. High figures of merit calculated at 1200 K (0.65 for Sr2PtSe and 0.38 for Sr2PtTe) and ultralow thermal conductivity indicate that the compounds investigated are good thermoelectric materials.