Copper Intercalation Effect on Thermoelectric Performance of Pristine Tin Selenide

Abstract

Pristine tin selenide (SnSe) and copper (Cu) doped SnSe single crystals are grown by direct vapour transport technique. The energy dispersive X-ray, X-ray diffraction and Raman spectroscopic analysis of grown crystals show preferred stoichiometry having a single phase othorhombic SnSe. The electrical conductivity of SnSe and Cu doped SnSe are 24.24 and 106.06 S m⁻¹ at 310 K respectively which increase as temperature increases. Carrier concentration of grown single crystals are evaluated by the Hall effect. Lattice thermal conductivity of pristine SnSe is 0.61 W mK⁻¹, that decreased by copper doping to 0.44 W mK⁻¹ at 310 K and for both the crystals it shows decrement as temperature increases to 483 K. Seebeck coefficient of the grown SnSe and Cu doped SnSe are positive and obtained values are 536.44 and 492.90 µV K⁻¹ respectively at 310 K that confirm the p-type semiconducting nature. Power factor, Figure of merit and thermoelectric compatibility factor of grown pristine SnSe is 0.25 × 10⁸ µV mK⁻², 0.005 and 0.02 Volt⁻¹ respectively and shows improvement in Cu doped SnSe, i.e., 0.08 × 10⁸ µV mK⁻², 0.017 and 0.07 Volt⁻¹ respectively at 310 K. This shows Cu doping in SnSe makes it an effective thermoelectric device contender.