Enhanced thermoelectric properties of Sb2Te3/CH3NH3I hybrid thin films by post-annealing

Abstract

In this work, to improve the ZT value of Sb₂Te₃, a novel concept of inorganic–organic hybridization is presented and Sb₂Te₃/CH₃NH₃I hybrid thin films have been prepared via a post-annealing involved sequential sputtering/evaporation method. The results show that the crystallinity of the thin films is greatly improved after post-annealing with preferential orientations of (006) and (009) at an appropriate temperature, leading to an obvious enhancement of electrical conductivity. Additionally, the hybrid thin films show uniform nano-sized grainy structures and the organic component CH₃NH₃I has been successfully incorporated into the hybrid system in a stable state, thus resulting in an increase of the Seebeck coefficient and decrease of the thermal conductivity based on the energy filtering effect. As expected, a maximum room-temperature ZT value of 0.56 for the Sb₂Te₃/CH₃NH₃I hybrid thin film annealed at 573 K can be obtained. This outcome further demonstrates great potential for the inorganic–organic hybrid thin film in low temperature application scenarios.