Enhancing the power factor of p-type BiSbTe films via deposited with/without Cr seed layer

Highlights: • p-type Bi_9.0Sb_30.5Te_60.5 film with/without Cr substrates was deposited. • Control of microstructure and transport properties via energy filtering is provided. • Cr seed layer can enhance both electrical conductivity and the Seebeck coefficient. • PF of 6.8 mW/ (m⋅K²) at 375 K was achieved for the Cr/BiSbTe film. -- Abstract: The thermoelectric effect is an efficient method to use waste heat as a primary source of electrical energy. Being a room temperature thermoelectric thin film, p-type BiSbTe is one of the best candidates owing to the combined high efficiency and large power factor for future technological applications. Novel approaches have emerged in recent decades with the aim of enhancing the thermoelectric properties of BiSbTe thin films. The method involves using Cr as an adhesion and seed layer for controlling microstructure and transport properties via the energy filtering of high-energy carriers. The heterostructure of Cr/BiSbTe film demonstrates the best electrical transport performance, where the Seebeck coefficient and the electrical conductivity are 425 µV/K and 25 S/m* 10³ in the vicinity of room temperature. The power factor of Cr/BiSbTe was reported to be 6.8 mW/mK² at 375 K, which was approximately seven times higher than the film without the Cr layer. We conclude that the inclusion of the Cr seed layer can notably improve the electrical transport properties of p-type BiSbTe films.