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

Recently synthesized novel phase of germanium selenide (γ-GeSe) adopts a hexagonal lattice and surprisingly high conductivity than graphite. This triggers great interests in exploring its potential for thermoelectric applications. Herein, we explored the performance monolayer γ-GeSe other isostructural γ-phase group-IV monochalcogenides γ-GeX (X = S, Se Te) using density functional theory Boltzmann transport theory. A superb is revealed with figure merit ZT value up to 1.13–2.76 n-type doping at moderate carrier concentration 4.73–2.58 × 1012 cm−2 between 300 600 K. rooted rich pocket states flat plateau levels around electronic band edges, leading promoted concentrations conductivity, limited thermal conductivity. Our work suggests that promising candidate medium-temperature