Tuning SnSe/SnS hetero-interfaces to enhance thermoelectric performance

With the development of nanotechnology, thermoelectric materials with complex heterogeneous nanostructure offer a promising approach to improve the thermoelectric performance. In this work, SnSe/SnS hetero-nanosheet was tuned by the epitaxial growth of SnSe on the few layers of SnS nanosheets. The heterojunction interface can optimize the carrier/phonon transport behavior by energy filtering effect and scattering the phonon in multiple scales. Compared with pristine SnSe, the power factor of SnSe/SnS hetero-nanosheet increases from 2.2[Formula: see text][Formula: see text]V/cmK2 to 3.21[Formula: see text][Formula: see text]V/cmK2 at 773[Formula: see text]K, whereas the thermal conductivity decreases significantly from 0.65[Formula: see text]W[Formula: see text][Formula: see text][Formula: see text]m[Formula: see text] to 0.48[Formula: see text]W[Formula: see text][Formula: see text][Formula: see text]m[Formula: see text] at 773[Formula: see text]K. The maximum ZT of 0.5 is obtained at 773[Formula: see text]K in the SnSe/SnS hetero-nanosheets, which is 89% higher than pristine SnSe. This approach is proved to be a promising strategy to design high performance thermoelectric materials.