Luo Chen, Wu Jianfeng, Zhang Xinlei, Fu Qiang, Wang Wenhui, Yu Yuanfang, Zeng Peiyu, Ni Zhenhua, Zhang Jialin, Lu Junpeng
School of Physics, Key Laboratory of Quantum Materials and Devices of Ministry of Education, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 211189, People's Republic of China.
School of Integrated Circuits, Southeast University, Nanjing 210096, People's Republic of China.
Nanotechnology. 2024 Jun 20;35(36). doi: 10.1088/1361-6528/ad568e.
Optimizing the width of depletion region is a key consideration in designing high performance photovoltaic photodetectors, as the electron-hole pairs generated outside the depletion region cannot be effectively separated, leading to a negligible contribution to the overall photocurrent. However, currently reported photovoltaic mid-infrared photodetectors based on two-dimensional heterostructures usually adopt a single pn junction configuration, where the depletion region width is not maximally optimized. Here, we demonstrate the construction of a high performance broadband mid-infrared photodetector based on a MoS/b-AsP/MoSnpn van der Waals heterostructure. The npn heterojunction can be equivalently represented as two parallel-stacked pn junctions, effectively increasing the thickness of the depletion region. Consequently, the npn device shows a high detectivity of 1.3 × 10cmHzWat the mid-infrared wavelength, which is significantly improved compared with its single pn junction counterpart. Moreover, it exhibits a fast response speed of 12 μs, and a broadband detection capability ranging from visible to mid-infrared wavelengths.
优化耗尽区宽度是设计高性能光伏光电探测器的关键考虑因素，因为在耗尽区之外产生的电子-空穴对无法有效分离，导致对整体光电流的贡献可忽略不计。然而，目前报道的基于二维异质结构的光伏中红外光电探测器通常采用单 pn 结结构，其中耗尽区宽度并未得到最大程度的优化。在此，我们展示了基于 MoS₂/b-AsP/MoS₂ npn 范德华异质结构构建的高性能宽带中红外光电探测器。该 npn 异质结可等效表示为两个平行堆叠的 pn 结，有效增加了耗尽区的厚度。因此，该 npn 器件在中红外波长处显示出 1.3×10¹² cmHz¹/²W⁻¹ 的高探测率，与单 pn 结器件相比有显著提高。此外，它具有 12 μs 的快速响应速度，以及从可见光到中红外波长的宽带探测能力。
