Thermoelectric performance of bilayer and multilayer SnSe/Bi2Te3 thin films prepared by physical vapor deposition

Tin Selenide is a promising material for mid-temperature thermoelectric application where as Bismuth Telluride is mainly known for its room temperature thermoelectric application. The combination of these two materials would probably enhance the performance of the thermoelectric generator. The present work deals with bilayer and multilayer thin film deposition of Tin Selenide and Bismuth Telluride in glass substrates by physical vapor deposition. Then the deposited thin films were given a post-annealing treatment for 30 minutes at 323K, 423K, and 523K. The structure and morphology of the thin films have been studied using XRD, SEM, FESEM and AFM. The Seebeck Coefficient and Electrical conductivity of the bilayer and multilayer thin films were studied using the Seebeck Coefficient measurement system as temperature as function in a range of 300K to 573K. The maximum Seebeck Coefficent of -350μV/K was obtained for both bilayer and multilayer thin film at 573K. The highest electrical conductivity of 220S/m and 170S/m were obtained for bilayer and multilayer thin film respectively. The power factor that gives the thermoelectric generator’s performance was calculated from the Seebeck Coefficient and Electrical conductivity. The overall power factor for 573K annealed films of bilayer and multilayer thin films increases with rise in temperature. The maximum obtained power factor for bilayer and multilayer thin films were 25W/K2m and 18 W/K2m respectively.