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Electret Modulation Strategy to Enhance the Photosensitivity Performance of Two-Dimensional Molybdenum Sulfide
journal contributionposted on 2023-12-13, 08:30 authored by Lian Hu, Xin Li, Xinyu Guo, Minxuan Xu, Yueqin Shi, Nduwarugira B. Herve, Rong Xiang, Qi Zhang
Due to the limited light absorption efficiency of atomic thickness layers and the existence of quenching effects, photodetectors solely made of transition metal dichalcogenides (TMDs) have exhibited an unsatisfactory detection performance. In this article, electret/TMD hybridized devices were proposed by vertically coupling a MoS2 channel and the PTFE film, which reveals an optimized photodetection behavior. Negative charges were generated in the PTFE layer through the corona charging method, akin to applying a negative bias on the MoS2 channel in lieu of a traditional voltage-driven back gate. Under a charging voltage of −6 kV, PTFE/MoS2 devices reveal improved photodetection performance (Rhybrid = 67.95A/W versus Ronly = 3.37 A/W, at 470 nm, 1.20 mW cm–2) and faster recovery speed (τd(hybrid) = 2000 ms versus τd(only) = 2900 ms) compared to those bare MoS2 counterparts. The optimal detection performance (2 orders of magnitude) was obtained when the charging voltage was −2 kV, limited by the minimum of the carrier density in MoS2 channels. This study provides an alternative strategy to optimize optoelectronic devices based on the 2D components through non-voltage-driven gating.
− 6 kvtransition metal dichalcogenidestmd hybridized devicesphotodetectors solely madeoptimized photodetection behaviorfaster recovery speedatomic thickness layers20 mw cm− 2 kvunsatisfactory detection performanceoptimal detection performancedriven back gatecorona charging methodhybrid subhybrid ) subelectret modulation strategy2 sub sub) subphotosensitivity performance2 ordersr driven gatingalternative strategy>< subcharging voltagevertically couplingstudy providesquenching effectsnegative chargesnegative biascarrier density470 nm2d components2900 ms