Work

Formation and interface characterization of Bi 2 Se 3 /YBa 2 Cu 3 O 7 thin films via two‐step growth using cracked‐Se technique

Year: 2025

Type: article

Abstract: Achieving a high‐quality interface between the topological insulator Bi 2 Se 3 and the high‐critical temperature superconductors YBa 2 Cu 3 O 7 (YBCO) remains challenging because of the rough surface morphology and elemental interdiffusion originating from YBCO. In previous studies, the Bi 2 Se 3 thin films directly deposited on YBCO exhibited poor crystallinity, which was significantly improved after a subsequent cracked‐Se treatment, although substantial elemental diffusion from YBCO still persisted. Here, we employ a two‐step growth technique consisting of an initial Bi thin‐film deposition followed by a cracked‐Se treatment and additionally introduce a thin Se buffer layer before the Bi deposition to effectively mitigate elemental diffusion. Structural and chemical characterizations demonstrate that the Se buffer layer effectively suppresses Cu diffusion, facilitates the formation of a uniform quintuple‐layer structure, and improves the crystallinity of the Bi 2 Se 3 thin films. Electrical measurements showed that YBCO with the Se buffer exhibits a higher superconducting transition temperature (~10 K) than the sample without the buffer (~4 K).

Source: ETRI Journal

DOI: 10.4218/etrij.2025-0235

Authors: Woo‐Jung Lee, Tae‐Ha Hwang, Dae‐Hyung Cho, Jaehan Park, Mann‐Ho Cho, Yong‐Duck Chung

Institutions: Electronics and Telecommunications Research Institute, Korea University of Science and Technology, Yonsei University

Language: English

Topic: Topological Materials and Phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: diamond

Funders: National Research Foundation, Electronics and Telecommunications Research Institute, National Research Foundation of Korea, Ministry of Science and ICT, South Korea

Awards: G1729275002, G4178803602, G558949674