Cottam Nathan D, Dewes Benjamin T, Shiffa Mustaqeem, Cheng Tin S, Novikov Sergei V, Mellor Christopher J, Makarovsky Oleg, Gonzalez David, Ben Teresa, Patanè Amalia
School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
University Research Institute on Electron Microscopy and Materials, IMEYMAT, Universidad de Cadiz, 11510 Cadiz, Spain.
ACS Appl Nano Mater. 2024 Jul 31;7(15):17553-17560. doi: 10.1021/acsanm.4c02685. eCollection 2024 Aug 9.
Two-dimensional semiconductors (2DSEM) based on van der Waals crystals offer important avenues for nanotechnologies beyond the constraints of Moore's law and traditional semiconductors, such as silicon (Si). However, their application necessitates precise engineering of material properties and scalable manufacturing processes. The ability to oxidize Si to form silicon dioxide (SiO) was crucial for the adoption of Si in modern technologies. Here, we report on the thermal oxidation of the 2DSEM gallium selenide (GaSe). The nanometer-thick layers are grown by molecular beam epitaxy on transparent sapphire (AlO) and feature a centro-symmetric polymorph of GaSe. Thermal annealing of the layers in an oxygen-rich environment promotes the chemical transformation and full conversion of GaSe into a thin layer of crystalline GaO, paralleled by the formation of coherent GaO/AlO interfaces. Versatile functionalities are demonstrated in photon sensors based on GaSe and GaO, ranging from electrical insulation to unfiltered deep ultraviolet optoelectronics, unlocking the technological potential of GaSe nanostructures and their amorphous and crystalline oxides.
基于范德华晶体的二维半导体（2DSEM）为超越摩尔定律和传统半导体（如硅（Si））限制的纳米技术提供了重要途径。然而，它们的应用需要对材料特性进行精确设计以及可扩展的制造工艺。将硅氧化形成二氧化硅（SiO₂）的能力对于现代技术中硅的采用至关重要。在此，我们报告二维半导体硒化镓（GaSe）的热氧化情况。通过分子束外延在透明蓝宝石（Al₂O₃）上生长出纳米厚的层，其具有GaSe的中心对称多晶型物。在富氧环境中对这些层进行热退火促进了化学转变，并使GaSe完全转化为一层结晶Ga₂O₃，同时形成了相干的Ga₂O₃/Al₂O₃界面。基于GaSe和Ga₂O₃的光子传感器展示了多种功能，从电绝缘到未经过滤的深紫外光电子学，释放了GaSe纳米结构及其非晶态和晶态氧化物的技术潜力。
