Shiffa Mustaqeem, Dewes Benjamin T, Bradford Jonathan, Cottam Nathan D, Cheng Tin S, Mellor Christopher J, Makarovskiy Oleg, Rahman Kazi, O'Shea James N, Beton Peter H, Novikov Sergei V, Ben Teresa, Gonzalez David, Xie Jiahao, Zhang Lijun, Patanè Amalia
School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
University Research Institute on Electron Microscopy and Materials, IMEYMAT, Universidad de Cádiz, Cádiz, 11510, Spain.
Small. 2024 Feb;20(7):e2305865. doi: 10.1002/smll.202305865. Epub 2023 Oct 5.
2D semiconductors (2SEM) can transform many sectors, from information and communication technology to healthcare. To date, top-down approaches to their fabrication, such as exfoliation of bulk crystals by "scotch-tape," are widely used, but have limited prospects for precise engineering of functionalities and scalability. Here, a bottom-up technique based on epitaxy is used to demonstrate high-quality, wafer-scale 2SEM based on the wide band gap gallium selenide (GaSe) compound. GaSe layers of well-defined thickness are developed using a bespoke facility for the epitaxial growth and in situ studies of 2SEM. The dominant centrosymmetry and stacking of the individual van der Waals layers are verified by theory and experiment; their optical anisotropy and resonant absorption in the UV spectrum are exploited for photon sensing in the technological UV-C spectral range, offering a scalable route to deep-UV optoelectronics.
二维半导体（2SEM）能够变革诸多领域，从信息与通信技术到医疗保健。迄今为止，其制造的自上而下方法，如用“胶带”剥离块状晶体，虽被广泛应用，但在功能的精确工程设计和可扩展性方面前景有限。在此，一种基于外延的自下而上技术被用于展示基于宽带隙硒化镓（GaSe）化合物的高质量、晶圆级二维半导体。使用定制的外延生长和二维半导体原位研究设备，制备出具有明确厚度的GaSe层。通过理论和实验验证了单个范德华层的主要中心对称性和堆叠情况；利用它们在紫外光谱中的光学各向异性和共振吸收，在技术上的紫外-C光谱范围内进行光子传感，为深紫外光电子学提供了一条可扩展的途径。
