A highly crystalline single- or few-layered 2D-MoS2 induces a high dark current, due to which an extremely small photocurrent generated by a few photons can be veiled or distorted. In this report, we show that suppression in the dark current with the enhancement in the photocurrent of a 2D-based photodetector, which is a prerequisite for photoresponse enhancement, can be achieved by constructing an ideal p‐n junction based on functionalizing n-type 2D-MoS2 with p-type quantum dots (QDs). Highly crystalline solution-processed manganese oxide QDs (MnO QDs) are synthesized via the pulsed femtosecond laser ablation technique in ethanol. The ablated MnO QDs are spray-coated on an exfoliated 2D-MoS2 substrate with interdigitated Au electrodes through N2-assisted spraying. In the resulting MnO QD-decorated 2D-MoS2 photodetector with a heterojunction, dark current is reduced and is accompanied by photocurrent enhancement, thereby markedly improving the photoresponsivity and detectivity of MoS2-based devices. To elucidate the underlying mechanisms contributing to this enhancement, power- and wavelength-dependent photoresponses, along with material characterizations based on spectroscopic, chemical, morphological measurements, and analyses, are discussed.

中文翻译：

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p型MnO量子点装饰的n型2D-MoS2基光电探测器中暗电流降低伴随光电流增强

高度结晶的单层或几层 2D-MoS2 会引起高暗电流，因此由几个光子产生的极小光电流可能会被掩盖或扭曲。在本报告中，我们展示了通过构建基于功能化 n 型的理想 p-n 结，可以抑制暗电流并增强基于 2D 的光电探测器的光电流，这是光响应增强的先决条件。具有 p 型量子点 (QD) 的 2D-MoS2。通过脉冲飞秒激光烧蚀技术在乙醇中合成高度结晶的溶液处理的氧化锰量子点 (MnO QDs)。通过 N2 辅助喷涂，将烧蚀的 MnO QD 喷涂在剥落的 2D-MoS2 基板上，并带有交叉指型的 Au 电极。在得到的带有异质结的 MnO QD 装饰的 2D-MoS2 光电探测器中，暗电流降低并伴随着光电流增强，从而显着提高了基于 MoS2 的器件的光响应性和探测率。为了阐明促成这种增强的潜在机制，讨论了与功率和波长相关的光响应，以及基于光谱、化学、形态测量和分析的材料表征。