Global structure search for new 2D PtSSe allotropes and their potential for thermoelectirc and piezoelectric applications

Abstract

Two new phases of pentagon-based 2D PtSSe , named α-penta- and β-penta-PtSSe, are identified based on global structure search method. We demonstrate that the two structures are dynamically, thermally and mechanically stable and exhibit prior thermoelectric and piezoelectric performances, suggesting their great potential for thermoelectric and piezoelectric applications. The highest ZT values of α-penta- and β-penta-PtSSe reach 0.60 and 1.13 at 800 K, respectively. Besides, β-penta-PtSSe possesses a large intrinsic piezoelectric response with d16 = 1.30 pm/V. This study expands the family of 2D TMDs, and throws new light on the explorations of new materials with high-performance thermoelectric and piezoelectric properties.