Effect of Cu Doping into the Ga Site on the Thermoelectric Properties of AgGaTe₂ with Chalcopyrite Structure

Abstract

In the present study, the effect of Cu doping into the Ga site on the thermoelectric properties of AgGaTe₂ with chalcopyrite structure was investigated. The samples of AgGa_1-xCu_xTe₂ (x=0, 0.5, and 0.1) were prepared by a solid-state reaction followed by hot pressing. The electrical resistivity, Seebeck coefficient and thermal conductivity were measured from room temperature to about 680 K. The Cu doping increased the carrier concentration, leading to enhancement of the dimensionless figure of merit ZT of AgGaTe₂. The maximum ZT value was 0.45 at 680 K obtained in AgGa_0.9Cu_0.1Te₂, which was approximately two times higher than that of stoichiometric AgGaTe₂.