Seebeck Coefficient Enhancement by Quantum Confinement Effect in Superlattice Nanocomposites

Thermoelectric devices enable the bidirectional conversion between thermal and electrical energy, which has great potential in energy harvest and thermal management, etc. This work proves experimentally that the quantum confinement effect could improve the thermoelectric properties of low-dimensional film materials effectively. The quantum wells formed by embedding ErAs nanoparticles with diameter of around 2 nm in In_0.53Ga_0.47As matrix lead to drastic changes in the material band structure and convert the semimetal ErAs into a semiconductive state. The size confinement increases the asymmetry in the distribution of the density of electron states near the Fermi level and thus improves the Seebeck coefficient. Here, we report that the Seebeck coefficient and power factor of In_0.53Ga_0.47As films assembled with ErAs nanoparticles are increased by 2.2 times and 5 times at 516 K, respectively.