Creation of bismuth layered materials with black phosphorus structure and control of their electronic structures

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02617
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 29020:Thin film/surface and interfacial physical properties-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Nakatsuji Kan 東京工業大学, 物質理工学院, 准教授 (80311629)
• Co-Investigator(Kenkyū-buntansha): 平山 博之 東京工業大学, 理学院, 教授 (60271582)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 表面電子状態 / ビスマス超薄膜 / 光電子分光 / 走査トンネル顕微鏡

Outline of Final Research Achievements

Bi(110) ultra-thin films with black-phosphorous-like (BP-like) structure attract much interest as a candidate of two-dimensional topological insulator depending on its structural strain and charged states. In the present study, the atomic and electronic structures of Bi(110) ultra-thin films grown on silicon substrates are systematically investigated by angle-resolved photoelectron spectroscopy and scanning tunneling microscopy. The process of the extremely flat film growth with BP-like structure in a wide area was revealed through precise analysis of atomic and electronic structures. It was also revealed that the charge transfer at the interface of the film and the substrate could be controlled by the substrate doping condition and surface superstructures.

Free Research Field

表面界面物性

Academic Significance and Societal Importance of the Research Achievements

黒リン構造のBi(110)超薄膜は、2次元トポロジカル絶縁体の候補として、その電子状態が大変興味深いにもかかわらず、研究例は少ない状態であった。本研究によってその成長過程と電子状態を詳細に明らかにできたことは、薄膜電子物性の観点だけでなく、結晶成長の観点からも学術的な意義が大きいと考えている。また、デバイス整合性のよい半導体基板を用いて将来的に半導体技術で電荷量を制御する可能性が示されたことは、社会的にも意義深いことと考えている。