Influence of the planar orientation of the substrate on thermoelectric response of SnSe thin films

We report thermoelectric performance in the temperature range of 300 K–800 K of SnSe thin films on r-, a-, and c-plane sapphire substrates grown by pulsed laser deposition. Several state of the art characterization techniques such as XRD, TEM, SEM, and XPS were used to thoroughly characterize the thin films. Thermal conductivity of these films were measured at room temperature using 3ω technique. Planar orientation of the substrate was found to influence the thermoelectric performance of SnSe thin films very significantly. SnSe thin films grown on r-plane substrate showed the lowest thermal conductivity of 0.35 W/m.K at 300 K; the highest power factor and ZT values of 1.96 μW/cm.K ² and 0.45, respectively at 800 K. These results for SnSe thin films is a ground breaking and has a potential to lead to efficient thin films thermoelectric modules.