Influence of post deposition annealing on thermoelectric properties of In2Se3 thin films

Abstract

In the present work, thermoelectric properties of thin films of In2Se3 are explored, with its low thermal conductivity and high electrical conductivity simultaneously, reported for the bulk ceramics and improved results for the doped systems for both cation and anion sites. Here, In2Se3 thin films are grown using thermal evaporation technique and the effect of post deposition annealing on the thermoelectric properties of In2Se3 thin films are studied. XRD, Raman and UV–visible spectroscopy show that the as grown film corresponds to α-In2Se3 phase which gets transformed to the γ-phase of In2Se3 upon annealing at 300 °C. The Hall measurements indicate that the films exhibit a high electron mobility and electrical conductivity. 3ω-method is employed for the thermal conductivity measurements of the as grown thin films of In2Se3 which is found to be 0.75 Wm−1K−1. Thermoelectric properties including the power factor and the ZT values are found to reach as high as 12.04 μW m−1K−2 and 4.9 × 10−3 respectively for the films post annealed at 300 °C. Our findings pave the simple way of energy generation based on the waste heat dissipation with the device size of few nm for the next generation device applications.