Extraordinary linear dynamic range in laser-defined functionalized graphene photodetectors.
Extraordinary linear dynamic range in laser-defined functionalized graphene photodetectors.
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DOI：
10.1126/sciadv.1602617
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发表时间：
2017-05
期刊：
影响因子：
13.6
通讯作者：
Russo S
中科院分区：
文献类型：
--
作者：
De Sanctis A;Jones GF;Wehenkel DJ;Bezares F;Koppens FHL;Craciun MF;Russo S
石墨烯的猝灭热电效应导致光电探测器线性动态范围的显著增加。基于石墨烯的光电探测器表现出机械灵活性、大工作带宽和宽带光谱响应。然而，它们的线性动态范围（LDR）受到石墨烯固有的热载流子动力学的限制，这导致在低入射功率下线性光响应偏离。同时，热载流子的倍增导致光活性区域在几微米的距离上被涂抹，限制了石墨烯在高分辨率应用中的使用。我们提出了一种利用激光照射在fecl3 -插层石墨烯中进行光活性结工程的新方法。在这些平面结处测量的光电流显示出非凡的线性响应，其LDR值至少是其他石墨烯器件（44 dB）的4500倍，同时在不需要封装的情况下保持对环境污染的高稳定性。观察到的光响应是纯光伏的，表明热载子效应完全猝灭。这些结果为设计具有前所未有的LDR的超薄光电探测器铺平了道路，用于高清成像和传感。
Quenching thermoelectric effects in graphene leads to an extraordinary increase of the linear dynamic range in photodetectors. Graphene-based photodetectors have demonstrated mechanical flexibility, large operating bandwidth, and broadband spectral response. However, their linear dynamic range (LDR) is limited by graphene’s intrinsic hot-carrier dynamics, which causes deviation from a linear photoresponse at low incident powers. At the same time, multiplication of hot carriers causes the photoactive region to be smeared over distances of a few micrometers, limiting the use of graphene in high-resolution applications. We present a novel method for engineering photoactive junctions in FeCl3-intercalated graphene using laser irradiation. Photocurrent measured at these planar junctions shows an extraordinary linear response with an LDR value at least 4500 times larger than that of other graphene devices (44 dB) while maintaining high stability against environmental contamination without the need for encapsulation. The observed photoresponse is purely photovoltaic, demonstrating complete quenching of hot-carrier effects. These results pave the way toward the design of ultrathin photodetectors with unprecedented LDR for high-definition imaging and sensing.