Augmented Quantum Yield of a 2D Monolayer Photodetector by Surface Plasmon Coupling
Augmented Quantum Yield of a 2D Monolayer Photodetector by Surface Plasmon Coupling
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DOI：
10.1021/acs.nanolett.7b05060
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发表时间：
2018-04-01
期刊：
影响因子：
10.8
通讯作者：
Jeong, Mun Seok
中科院分区：
文献类型：
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作者：
Bang, Seungho;Ngoc Thanh Duong;Jeong, Mun Seok
单层（1L）过渡金属二硫属化物（TMDC）因其直接带隙和宽吸收范围（紫外线到红外线）而成为纳米级光电器件的有前途的材料。然而，由于 1L-TMDC 的光量子产率 (QY) 极低，因此不能轻易用于实际光电器件应用（例如光电探测器、太阳能电池和发光二极管）。在这项研究中，基于银纳米线（NW）网络的表面等离子体（SP）成功实现了高增益1L-MoS2光电探测器。通过对由 1L-MoS2 和 Ag NW 网络组成的混合结构进行系统光学表征，确定强烈的 SP 和应变弛豫效应会显着增强光学 QY。光致发光（PL）发射急剧增加了 560 倍，并且主峰转移到 1L-MoS2 的中性激子。因此，混合 1L-MoS2 光电探测器的整体光电流比原始 1L-MoS2 光电探测器好 250 倍。此外，混合光电探测器的光响应率和光电探测率有效提高了约1000倍。这项研究为实现基于TMDC的高效光电器件提供了一种新方法。
Monolayer (1L) transition metal dichalcogenides (TMDCs) are promising materials for nanoscale optoelectronic devices because of their direct band gap and wide absorption range (ultraviolet to infrared). However, 1L-TMDCs cannot be easily utilized for practical optoelectronic device applications (e.g., photodetectors, solar cells, and light-emitting diodes) because of their extremely low optical quantum yields (QYs). In this investigation, a high-gain 1L-MoS2 photodetector was successfully realized, based on the surface plasmon (SP) of the Ag nanowire (NW) network. Through systematic optical characterization of the hybrid structure consisting of a 1L-MoS2 and the Ag NW network, it was determined that a strong SP and strain relaxation effect influenced a greatly enhanced optical QY. The photoluminescence (PL) emission was drastically increased by a factor of 560, and the main peak was shifted to the neutral exciton of 1L-MoS2. Consequently, the overall photocurrent of the hybrid 1L-MoS2 photodetector was observed to be 250 times better than that of the pristine 1L-MoS2 photodetector. In addition, the photoresponsivity and photodetectivity of the hybrid photodetector were effectively improved by a factor of similar to 1000. This study provides a new approach for realizing highly efficient optoelectronic devices based on TMDCs.