High-performance thermoelectric monolayer γ-GeSe and its group-IV monochalcogenide isostructural family

A new semi-metallic polymorph of γ-GeSe and its group-IV monochalcogenide with high conductivity for their application as the promising materials in TE devices. Our studies revealed that monolayer γ-GeSe is a superior thermoelectric material under n-type doping between 300 and 600 K. The figure of merit ZT value is up to 1.13–2.76 for n-type doping at a moderate carrier concentration of 4.73–2.58 × 1012 cm−2. This can be attributed to an ultralow effective mass, high density of electronic states and a moderate lattice thermal conductivity. All these transport physical quantities can provide some hints for carriers dynamics for nanoelectronics and thermoelectrics.