Single parabolic band behavior of thermoelectric p-type CuGaTe2

Abstract

The existence of a noticeable discrepancy in thermoelectric properties reported in the literature motivates the current work on the transport properties of CuGaTe₂. Taking Zn- and Mn-doping at the Ga site as an example, the hole concentration can be effectively tuned within 10¹⁸–10²⁰ cm⁻³ that enables a reliable assessment of the transport properties. It is evident that both temperature and carrier concentration dependent transport properties follow well within the framework of a single parabolic band approximation with a dominant carrier scattering by acoustic phonons. This work helps distinguish the effects that contribute to the high thermoelectric figure of merit zT in CuGaTe₂. The modeling further suggests that this compound can show a thermoelectric figure of merit of unity or higher, when further strategies are taken for reducing the lattice thermal conductivity and engineering the band structure.