Self-powered photodetectors constructed by two-dimensional (2D) materials are significant in advanced science and technology with the growing focus on green and energy-efficient solutions. The built-in electric field in photodetector drives efficient separation and transfer of photogenerated electron–hole pairs. However, traditional metal-2D material-metal structures have more interface defects and larger Schottky barrier to hinder carrier transport. In this work, an asymmetric electrode material structure is constructed by adding graphene to provide a more efficient transport channel for photogenerated carriers. Graphene electrodes can play a variety of roles in efficient separation and collection of photogenerated carriers, reducing the barrier and improving the contact quality. Compared with the device using symmetric gold electrodes, the device prepared with asymmetric contacts show optimized performance. The MoTe2/WSe2 heterostructure exhibits brilliant self-powered photoresponse (a responsivity of 268 mA/W and a detectivity of 7.48*1011 Jones). And the rise/decay times are up to 145μs/125μs. Additionally, the detector has a broadband detection capability from visible light to near-infrared. These results provide a promising and simple way to fabricate a MoTe2/WSe2 self-powered broadband photodetector with high performance

中文翻译：

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基于MoTe2/WSe2范德华异质结构的不对称接触，实现自供电宽带光电探测器的增强光响应


随着人们对绿色和节能解决方案的日益关注，由二维 (2D) 材料构建的自供电光电探测器在先进科学技术中具有重要意义。光电探测器中的内置电场驱动光生电子空穴对的有效分离和转移。然而，传统的金属-二维材料-金属结构具有更多的界面缺陷和更大的肖特基势垒来阻碍载流子传输。在这项工作中，通过添加石墨烯构建了不对称电极材料结构，为光生载流子提供更有效的传输通道。石墨烯电极可以在高效分离和收集光生载流子、降低势垒、提高接触质量等方面发挥多种作用。与使用对称金电极的器件相比，使用不对称接触制备的器件表现出优化的性能。 MoTe2/WSe2异质结构表现出出色的自供电光响应（响应度为268 mA/W，探测灵敏度为7.48*1011 Jones）。上升/衰减时间高达 145μs/125μs。此外，该探测器还具有从可见光到近红外的宽带探测能力。这些结果为制造高性能 MoTe2/WSe2 自供电宽带光电探测器提供了一种有前途且简单的方法