Low Contact Resistivity of Bi₂Te₃‐Based Films and Metals Interfaces Enabled by Orientation Regulation

Abstract The contact resistivity originating from the metal–semiconductor interface is a crucial factor for conversion efficiency of thermoelectric films devices. Due to anisotropic nature of state‐of‐art Bi₂Te₃ films, the contact resistivity also needs to match with the different orientations in/out‐plane film configurations. Here, a series of bismuth telluride (Bi₂Te₃) films with different orientations are deposited, and the contact resistivity between Ti/Cr/Cu and Bi₂Te₃‐based films is studied in detail. The increased (00l) orientation can effectively reduce the contact resistivity mainly due to the enhanced Tunneling effect. Finally, a low contact resistivity of 0.84 µΩ cm² is observed in highly (00l)‐orientated Bi₂Te₃ film in contact with Cr. This work provides an effective method to control contact resistivity by adjusting the orientation of film, and also provides guidance on how to further improve the performance of thin film‐TEDs with different configurations.