In this study,large-scale Te-doped polycrystalline SnSe nanopowders were synthesized by a facile hydrothermal approach and the effect of Te doping on the thermoelectric properties of SnSe was fully investigated.It is found that the carrier concentration increases due to the reduction of band gap by alloying with Te,which contributes to significant enhancement of electrical conductivity especially at room temperature.Combined with the moderated Seebeck coefficient,a high power factor of 4.59 μW cm-1 K-2 is obtained at 773 K.Furthermore,the lattice thermal conductivity is greatly reduced upon Te substitution owing to the atomic point defect scattering.Benefiting from the synergistically optimized both electrical-and thermal-transport properties by Te-doping,thermoelectric performance of polycrystalline SnSe is enhanced in the whole temperature range with a maximum ZT of ～0.79 at a relatively low temperature (773 K) for SnSe0.ssTe0.15.This study provides a low-cost and simple lowtemperature method to mass production of SnSe with high thermoelectric performance for practical applications