First-Principles Prediction of High-Pressure Phase and Thermoelectric Transport in SrAgP

Designing new materials for waste heat to electricityconversionis crucial in energy science. Herein, we have predicted a high-pressurephase of SrAgP, realized above 11 GPa pressure, for thermoelectricapplications. Density functional theory (DFT) and hybrid functional(HSE06) are used for a better understanding of the electronic structureand transport properties of the high-pressure phase of SrAgP. A nodalline semimetal (NLSM) phase is observed in DFT calculations, whichtransform into a trivial band gap phase on using HSE06 hybrid DFTfunctional. In thermoelectric transport, the maximum value of thedimensionless figure of merit (zT & SIM; 0.65)of high-pressure SrAgP is obtained at 800 K in the p-type region.The exciting feature in transport properties is the closely matching zT (& SIM;0.40) values between n-type and p-type regionsat 800 K, making high-pressure SrAgP interesting for device-basedapplications.