Electronic structure and thermal conductance of the MASnI3/Bi2Te3 interface: a first-principles study

To develop high-performance thermoelectric devices that can be created using printing technology, the interface of a composite material composed of MASnI 3 and Bi 2 Te 3 , which individually show excellent thermoelectric performance, was studied based on first-principles calculations. The structural stability, electronic state, and interfacial thermal conductance of the interface between Bi 2 Te 3 and MASnI 3 were evaluated. Among the interface structure models, we found stable interface structures and revealed their specific electronic states. Around the Fermi energy, the interface structures with Te II and Bi terminations exhibited interface levels attributed to the overlapping electron densities for Bi 2 Te 3 and MASnI 3 at the interface. Calculation of the interfacial thermal conductance using the diffuse mismatch model suggested that construction of the interface between Bi 2 Te 3 and MASnI 3 could reduce the thermal conductivity. The obtained value was similar to the experimental value for the inorganic/organic interface.