Full Thermoelectric Characterization of Stoichiometric Electrode-posited Thin Film Tin Selenide (SnSe)

Tin selenide (SnSe) has attracted much attention in the thermoelectric community since the discovery of the record ZT of 2.6 in single crystal tin selenide in 2014. There have been many reports since of the thermoelectric characterization of SnSe synthesized or manufactured by several methods, but so far none of these have concerned the electrodeposition of SnSe. In this work, stoichiometric SnSe was successfully electrodeposited at -0.50 V vs. SCE as shown by EDX, XPS, UPS and XRD. The full ZT of the electrodeposits were then fully measured. This was done by both a delamination technique to measure the Seebeck coefficient and electrical conductivity which showed a peak power factor of 4.2 and 5.8 μW m^-1 K^-2 for the as deposited and heat-treated films respectively. A novel modified transient 3-ω method was used to measure the thermal conductivity of the deposited films on the deposition substrate. This revealed the thermal conductivity to be similar to the ultralow thermal conductivity of single crystal SnSe, with a value of 0.34 W m^-1 K^-1 being observed at 313 K.