• 文献标题:   High-Responsivity Gate-Tunable Ultraviolet-Visible Broadband Phototransistor Based on Graphene-WS2 Mixed-Dimensional (2D-0D) Heterostructure
  • 文献类型:   Article
  • 作  者:   MUKHERJEE S, BHATTACHARYA D, PATRA S, PAUL S, MITRA RK, MAHADEVAN P, PAL AN, RAY SK
  • 作者关键词:   graphene, ws2 quantum dot, broadband, mixeddimensional heterostructure, phototransistor, stability
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244 EI 1944-8252
  • 通讯作者地址:  
  • 被引频次:   9
  • DOI:   10.1021/acsami.1c18999 EA JAN 2022
  • 出版年:   2022

▎ 摘  要

Recent progress in the synthesis of highly stable, eco-friendly, costeffective transition-metal dichalcogenide (TMDC) quantum dots (QDs) with their broadband absorption spectra and wavelength selectivity features have led to their increasing use in broadband photodetectors. With the solution-based processing, we demonstrate a superlarge (similar to 0.75 mm(2)), ultraviolet-visible (UV-vis) broadband (365-633 nm) phototransistor made of WS2 QDs-decorated chemical vapor deposited (CVD) graphene as the active channel with extraordinary stability and durability under ambient conditions (without any degradation of photocurrent until 4 months after fabrication). Here, colloidal zero-dimensional (0D) WS2 QDs are used as the photoabsorbing material, and graphene acts as the conducting channel. A high photoresponsivity (3.1 x 10(2) A/W), moderately high detectivity (similar to 8.9 x 10(8) Jones), and low noise equivalent power (similar to 9.7 x 10(-11) W/Hz0.5) are obtained at a low bias voltage (V-ds = 1 V) at an illumination of 365 nm with optical power as low as similar to 0.8 mu W/cm(2), which can be further tuned by modulating the gate bias. While comparing the photocurrent between two different morphologies of WS2 [QDs and two-dimensional (2D) nanosheets], a significant enhancement of photocurrent is observed in the case of QD-based devices. Ab initio density functional theory (DFT)-based calculations further support our observation, revealing the role of quantum confinement in enhanced photoresponse. Our work reveals a strategy toward developing a scalable, cost-effective, high-performance hybrid mixed-dimensional (2D-0D) photodetector with graphene-WS2 QDs for next-generation optoelectronic applications.