Composition-dependent anisotropic electrical transport and thermoelectric characteristics of CuxSn1−xSe alloy crystals

Single-crystalline CuxSn1−xSe alloys with compositions x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0 were systematically investigated to understand the influence of Cu incorporation on anisotropic charge transport and thermoelectric behavior. Temperature-dependent electrical resistivity measurements were performed along directions parallel and perpendicular to the crystallographic c-axis over the temperature range of 297–723 K using a two-probe configuration. The results reveal pronounced anisotropy in charge transport, indicating strong directional dependence of carrier conduction within the layered crystal framework. Activation energies associated with electrical conduction were estimated from Arrhenius-type analysis for both crystallographic orientations, providing insight into the transport mechanism and carrier excitation process. Thermoelectric power measurements were conducted from room temperature to 473 K to evaluate the nature of dominant charge carriers and composition-dependent thermoelectric response. In addition, room-temperature Hall-effect investigations were employed to determine key electronic transport parameters including Hall coefficient, carrier concentration, and carrier mobility. The study demonstrates that Cu substitution significantly modifies the electrical and thermoelectric characteristics of SnSe-based alloy crystals, suggesting their potential applicability in anisotropic thermoelectric and electronic device architectures.