Dynamic carrier transports and low thermal conductivity in <i>n</i> ‐type layered InSe thermoelectrics

Semiconductor InSe with wide bandgap and layered crystal structure is expected to be a promising thermoelectric material, its excellent plasticity brings great potential applications in flexible wearable devices. To advance performance, this work systematically investigates the carrier phonon transport properties n-type InSe. It found that compound presents an exceptional dynamic property due amphoteric indium (In+ In3+), which contributes favorable temperature-dependent increasing concentration. More importantly, S alloying InSe, concentration can further enhanced from ∼3.2 × 1013 cm–3 ∼4.8 1015 InSe0.97S0.03 at 300 K, because (χP ∼ 2.58) larger Pauling electronegativity than Se 2.55) induce more In3+ state increase matrix. This boosted benefits obviously power factor. Additionally, intrinsically low thermal conductivity ∼1.6 W m–1 K–1 K low-symmetry strong anharmonicity. indicates special make it as worth-expecting material.