# Two-dimensional InSe as a potential thermoelectric material

## TL;DR

This study explores the thermoelectric properties of monolayer InSe, revealing its potential as an efficient thermoelectric material due to its favorable electronic structure and transport characteristics.

## Contribution

It provides first-principles calculations of InSe's thermoelectric performance, highlighting its high power factor and the origins of its excellent thermoelectric properties.

## Key findings

- Maximum power factor of 0.049 W/K^2/m for p-type InSe at 300 K
- Large Seebeck coefficient due to 2 eV band gap
- High electrical conductivity from unique 2D density of states

## Abstract

Thermoelectric properties of monolayer indium selenide (InSe) are investigated by using Boltzman transport theory and first-principles calculations as a function of Fermi energy and crystal orientation. We find that the maximum power factor of p-type (n-type) monolayer InSe can be as large as 0.049 (0.043) W/K$^2$m at 300 K in the armchair direction. The excellent thermoelectric performance of monolayer InSe is attributed to both of its Seebeck coefficient and electrical conductivity. The large Seebeck coefficient originates from the moderate (about 2 eV) band gap of monolayer InSe as an indirect gap semiconductor, while its large electrical conductivity is due to its unique two-dimensional density of states (DOS), which consists of an almost constant DOS near the conduction band bottom and a sharp peak near the valence band top.