Enhanced Thermopower via Carrier Energy Filtering in Solution-Processable Pt-Sb2Te3 Nanocomposites

This work demonstrates the first solution-processable metal semiconductor nanocomposites with enhanced thermoelectric properties via carrier energy filtering. Platinum nanocrystals are embedded in a p-type antimony(III) telluride (Sb2Te3) semiconductor matrix, thus introducing band-bending potentials for holes. By scattering low energy holes, an increase in thermopower is observed. Introduction of Pt nanocrystals also increases carrier concentration thereby partially compensating for reduced electrical conductivity due to the decreased mobility. At room temperature, an improvement in thermoelectric power factor was achieved compared to that of the Sb2Te3 films. This work highlights the possibility of combining a diverse set of n- and p-type semiconductor matrices with nanocrystals to engineer and optimize energy-dependent carrier scattering with the ease of materials processing.