极化工程全二维石墨烯/铁电混合结构用于无持久性光响应
Polarization engineered all 2D Graphene/Ferroelectric hybrid for persistence-free photoresponse
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中文总结 AI 辅助
该研究通过集成原子级薄的滑动铁电体，制备了双层石墨烯-双层3R-MoS₂范德华光电探测器，实现了与温度无关的数十毫秒级快速响应，内部量子效率达10%，可重复检测光信号，为超灵敏光电器件提供了有前途平台。
中文摘要 AI 辅助
基于石墨烯的范德华混合光电探测器通常基于陷阱介导的光门机制工作，具有高灵敏度，但在重复光信号的快速检测方面表现不佳。因此，设计同时具备快速响应和高灵敏度的光电探测器一直存在困难。本研究通过在设计架构中集成原子级薄的滑动铁电体，同时实现了这两种特性，将半导体特性与能够有效调控界面光载流子动力学的本征极化场结合起来。我们制备了一种双层石墨烯-双层MoS₂（其中MoS₂为菱面体堆叠（3R）构型）范德华光电探测器，采用边缘接触的双栅场效应晶体管架构。3R-MoS₂的自发面外极化的光诱导调制，以及在面外位移场下载流子在双层石墨烯中的选择性限制，共同产生了可调的无持久性光响应。在此，3R-MoS₂中的光诱导极化变化产生了光控门控效应，该效应改变了双层石墨烯的静电环境，从而产生了与温度无关的光响应，其快速响应时间为数十毫秒（受测量仪器限制）。我们展示了对光信号的可重复检测，并在高灵敏度 regime 中研究了该结构的光子计数分辨率，在此 regime 中，我们确定其内部量子效率为10%，单次测量的最小可检测光子数为31。本研究突出了3R-MoS₂在调控界面电荷动力学方面的功能，并确立了石墨烯与铁电3R-MoS₂的混合结构作为超灵敏光电器件的有前途平台。
英文摘要
Graphene-based van der Waals hybrid photodetectors typically work on trap-mediated photogating mechanism, exhibiting high sensitivity, but under-perform in the fast detection of repetitive optical signals. Designing photodetectors that are simultaneously fast and highly sensitive has therefore remained difficult. In this work, we realize both attributes by integrating atomically thin sliding ferroelectrics in the design architecture, thereby uniting semiconducting properties with intrinsic polarization fields capable of efficiently governing interfacial photocarrier dynamics. We report a bilayer graphene-bilayer MoS2 (with MoS2 in a rhombohedrally stacked (3R) configuration) van der Waals photodetector with edge-contacted dual-gated field-effect transistor architecture. The photo-induced modulation in spontaneous out-of-plane polarization of 3R-MoS2 and selective confinement of charge carriers in bilayer graphene under an out-of-plane displacement field results in a tunable persistence-free photoresponse. Here, the photoinduced polarization change in 3R-MoS2 produces an optically controlled gating effect that alters the electrostatic environment of bilayer graphene, resulting in a temperature-independent photoresponse with rapid response times of the order of 10's of milliseconds (limited by the measurement instrument). We demonstrate reproducible detection of optical signals and examine the photon-counting resolution of this structure in high-sensitivity regimes, where we determine its internal quantum efficiency to be 10 percent with minimum detectable photon number of 31 in single shot measurements. This work highlights the functionality of 3R-MoS2 in manipulating the interfacial charge dynamics and establishes the hybrid of graphene and ferroelectric 3R-MoS2 as a promising platform for ultra-sensitive optoelectronic devices.
