Yan Yong, Yang Juehan, Du Juan, Zhang Xiaomei, Liu Yue-Yang, Xia Congxin, Wei Zhongming
Henan Key Laboratory of Photovoltaic Materials, School of Physics, Henan Normal University, Xinxiang, 453007, China.
State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences & Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100083, China.
Adv Mater. 2021 Jun;33(22):e2008761. doi: 10.1002/adma.202008761. Epub 2021 Apr 19.
Exploring 2D ultrawide bandgap semiconductors (UWBSs) will be conductive to the development of next-generation nanodevices, such as deep-ultraviolet photodetectors, single-photon emitters, and high-power flexible electronic devices. However, a gap still remains between the theoretical prediction of novel 2D UWBSs and the experimental realization of the corresponding materials. The cross-substitution process is an effective way to construct novel semiconductors with the favorable parent characteristics (e.g., structure) and the better physicochemical properties (e.g., bandgap). Herein, a simple case is offered for rational design and syntheses of 2D UWBS GaPS by employing state-of-the-art GeS as a similar structural model. Benefiting from the cosubstitution of Ge with lighter Ga and P, the GaPS crystals exhibit sharply enlarged optical bandgaps (few-layer: 3.94 eV and monolayer: 4.50 eV) and superior detection performances with high responsivity (4.89 A W ), high detectivity (1.98 × 10 Jones), and high quantum efficiency (2.39 × 10 %) in the solar-blind ultraviolet region. Moreover, the GaPS -based photodetector exhibits polarization-sensitive photoresponse with a linear dichroic ratio of 1.85 at 254 nm, benefitting from its in-plane structural anisotropy. These results provide a pathway for the discovery and fabrication of 2D UWBS anisotropic materials, which become promising candidates for future solar-blind ultraviolet and polarization-sensitive sensors.
探索二维超宽带隙半导体（UWBSs）将有助于下一代纳米器件的发展，如深紫外光电探测器、单光子发射器和高功率柔性电子器件。然而，新型二维UWBSs的理论预测与相应材料的实验实现之间仍存在差距。交叉取代过程是构建具有良好母体特性（如结构）和更好物理化学性质（如带隙）的新型半导体的有效方法。在此，通过采用最先进的GeS作为类似结构模型，提供了一个简单的案例用于二维UWBS GaPS的合理设计与合成。受益于用较轻的Ga和P对Ge进行共取代，GaPS晶体展现出大幅扩大的光学带隙（少层：3.94 eV，单层：4.50 eV）以及在日盲紫外区域具有高响应度（4.89 A W）、高探测率（1.98×10 Jones）和高量子效率（2.39×10%）的优异探测性能。此外，基于GaPS的光电探测器表现出偏振敏感光响应，在254 nm处的线性二向色比为1.85，这得益于其面内结构各向异性。这些结果为二维UWBS各向异性材料的发现和制造提供了一条途径，使其成为未来日盲紫外和偏振敏感传感器的有前途的候选材料。
