Ti-Doped CuGaTe₂ as a High-Performance Thermoelectric Material: Enhancing Thermoelectric Properties through N-Type Doping

CuGaTe 2 has attracted significant attention as a promising thermoelectric material due to its high Seebeck coefficient and moderate band gap. However, its intrinsic low carrier concentration and electrical conductivity limit the further enhancement of its thermoelectric performance. While most research has focused on p-type doping to increase hole carriers, excessive p-type doping can lead to carrier compensation effects, with some dopant atoms occupying Cu sites, thus weakening the doping effect. As a result, studies on n-type doping of CuGaTe 2 are relatively scarce. This study investigates the effects of n-type doping in CuGaTe 2 by introducing Ti as an n-type dopant, which effectively increases the electron carrier concentration. First-principles calculations and experimental results show that appropriate Ti doping not only improves the electrical transport properties but also significantly reduces the lattice thermal conductivity, leading to a notable increase in the ZT value. This research demonstrates that n-type doping can also improve the thermoelectric performance of CuGaTe 2 to some extent, providing insights for doping optimization in CuGaTe 2 .