Photon treatment effect on the surface and figure of merit of thermoelectric material Bi2Te3−xSex

The phase composition, structure, morphology, and thermal conductivity of Bi 2 Te 3− x Se x -based semiconductor solid solution after photon treatment (PT) were studied by X-ray diffractometry, SEM, TEM, and the laser flash techniques. It was revealed that PT leads to recrystallization of the subsurface layers of the solid solution with the formation of a heterogeneous nanocrystalline structure. The thermoelectric figure of merit of the semiconductor Bi 2 Te 3− x Se x (n-type) solid solution increases after PT due to modification of the surface layers. This is due to the decrease of the thermal conductivity of the studied material after PT.