In order to solve the increasingly urgent energy crisis, various new energy sources such as solar energy, wind energy, and nuclear energy have been continuously developed and utilized. The use of new energy requires high-quality energy-saving materials. The refrigeration and power generation system made of thermoelectric materials has many advantages such as small size, light weight, no mechanical noise, and no environmental pollution. Therefore, the research on thermoelectric materials is very important. In order to further improve the conversion efficiency of thermoelectric materials (thermoelectric figure of merit), research on it has slowly shifted from bulk to thin-film materials.