Ao Zhikang, Liu Chang, Ma Huifang, Lan Xiang, Zhang Jianhong, Zhang Baihui, Zhang Fen, Wang Zeran, Chen Peng, Zhong Mianzeng, Wang Guang, Zhang Zhengwei
Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, Hunan, 410083, China.
School of Flexible Electronics (Future Technologies), Institute of Advanced Materials, College of Materials Science and Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China.
Small. 2024 Nov;20(47):e2404897. doi: 10.1002/smll.202404897. Epub 2024 Aug 17.
The intrinsic low-symmetry crystal structures or external geometries of low-dimensional materials are crucial for polarization-sensitive photodetection. However, these inherently anisotropic materials are limited in variety, and their anisotropy is confined to specific crystal directions. Transforming 2D semiconductors, such as WSe, from isotropic 2D nanosheets into anisotropic 1D nanoscrolls expands their application in polarization photodetection. Despite this considerable potential, research on polarization photodetection based on nanoscrolls remains scarce. Here, the uniform crystalline orientation of WSe nanoscrolls is achieved conveniently and efficiently by applying ethanol droplets to vapor deposition-grown bilayer WSe nanosheets. Angle-resolved polarized Raman spectroscopy of WSe nanoscrolls demonstrates vibrational anisotropy. Photodetectors based on these nanoscrolls show competitive overall performance with a broadband detection range from 405 to 808 nm, a competitive on/off ratio of ≈900, a high detectivity of 3.4 × 10 Jones, and a fast response speed of ≈30 ms. Additionally, WSe nanoscroll-based photodetectors exhibit strong polarization-sensitive detection with a maximum dichroic ratio of 1.5. More interestingly, due to high photosensitivity, the WSe nanoscroll detectors can easily record sequential puppy images. This work reveals the potential of WSe nanoscrolls as excellent polarization-sensitive photodetectors and provides new insights into the development of high-performance optoelectronic devices.
低维材料固有的低对称晶体结构或外部几何形状对于偏振敏感光探测至关重要。然而，这些本质上各向异性的材料种类有限，并且它们的各向异性局限于特定的晶体方向。将二维半导体（如WSe）从各向同性的二维纳米片转变为各向异性的一维纳米卷，扩大了它们在偏振光探测中的应用。尽管有如此大的潜力，但基于纳米卷的偏振光探测研究仍然很少。在这里，通过将乙醇液滴施加到气相沉积生长的双层WSe纳米片上，可以方便且高效地实现WSe纳米卷的均匀晶体取向。WSe纳米卷的角分辨偏振拉曼光谱表明存在振动各向异性。基于这些纳米卷的光电探测器表现出具有竞争力的整体性能，宽带探测范围为405至808nm，竞争的开/关比约为900，高探测率为3.4×10琼斯，快速响应速度约为30ms。此外，基于WSe纳米卷的光电探测器表现出强烈的偏振敏感探测，最大二向色比为1.5。更有趣的是，由于高光敏性，WSe纳米卷探测器可以轻松记录小狗的连续图像。这项工作揭示了WSe纳米卷作为优异的偏振敏感光电探测器的潜力，并为高性能光电器件的发展提供了新的见解。
