Controlling the shape of hexagonal structure by growth condition improves the thermoelectric properties of p-type Bi-Te films

• Published in: Journal of the European Ceramic Society Vol. 43; no. 16; pp. 7493 - 7498
• Main Authors: Lan, Mingdi, Sun, Shang, Liu, Shiying, Li, Guojian, Wang, Zhiwei, Wang, Qiang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2023
• Subjects: Bi0.5Sb1.5Te3; Magnetron sputtering; Surface morphology; Thermoelectric film; Magnetron sputtering; Thermoelectric film; Surface morphology; Bi0.5Sb1.5Te3
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2023.07.053

Improving the thermoelectric (TE) properties of typical p-type Bi0.5Sb1.5Te3 film is crucial for power generation in film-based thermoelectric devices. The shape of the hexagonal structure in the Bi0.5Sb1.5Te3 film can be controlled by adjusting the magnetron sputtering parameters. The results indicate that a high nucleation rate under high sputtering power promotes island growth with a preferred orientation of (015). Thermal energy influences the growth in the in-plane direction along the (00 l) orientation and induces the c-axis orientation in the out-of-plane direction. Consequently, a dense layered hexagonal structure with a high grain boundary density is formed, leading to increased defect density, carrier concentration, and phonon scattering. In this case, the power factor reaches 3149.01 μW·m-1·K-2 at 480 K and the ZT value is 1.14 at 480 K. These results indicate that the film with a dense layered hexagonal structure enhances the TE properties.