College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China.
State Key Laboratory of Silicon Materials, College of Material Science, Zhejiang University, Hangzhou, Zhejiang, 310027, China.
Adv Mater. 2017 Jun;29(22). doi: 10.1002/adma.201700463. Epub 2017 Apr 4.
High-performance photodetectors operating over a broad wavelength range from ultraviolet, visible, to infrared are of scientific and technological importance for a wide range of applications. Here, a photodetector based on van der Waals heterostructures of graphene and its fluorine-functionalized derivative is presented. It consistently shows broadband photoresponse from the ultraviolet (255 nm) to the mid-infrared (4.3 µm) wavelengths, with three orders of magnitude enhanced responsivity compared to pristine graphene photodetectors. The broadband photodetection is attributed to the synergistic effects of the spatial nonuniform collective quantum confinement of sp domains, and the trapping of photoexcited charge carriers in the localized states in sp domains. Tunable photoresponse is achieved by controlling the nature of sp sites and the size and fraction of sp /sp domains. In addition, the photoresponse due to the different photoexcited-charge-carrier trapping times in sp and sp nanodomains is determined. The proposed scheme paves the way toward implementing high-performance broadband graphene-based photodetectors.
高性能光探测器在从紫外光、可见光到红外光的宽波长范围内运行，对于广泛的应用具有重要的科学和技术意义。在这里，提出了一种基于石墨烯及其氟功能化衍生物的范德华异质结构的光探测器。它始终表现出从紫外（255nm）到中红外（4.3µm）波长的宽带光响应，与原始石墨烯光探测器相比，响应度提高了三个数量级。宽带光电探测归因于 sp 畴的空间非均匀集体量子限制和 sp 畴中光激发电荷载流子的局域化状态的俘获的协同效应。通过控制 sp 位点的性质以及 sp /sp 畴的大小和分数，可以实现可调谐的光响应。此外，还确定了 sp 和 sp 纳米畴中不同光激发电荷载流子俘获时间的光响应。所提出的方案为实现高性能宽带基于石墨烯的光探测器铺平了道路。
