The hybrid structure of zero-dimensional (0D) graphene quantum dots (GQDs) and semiconducting two-dimensional (2D) MoS₂ has been investigated, which exhibit outstanding properties for optoelectronic devices surpassing the limitations of MoS₂ photodetectors where the GQDs extend the optical absorption into the near-UV regime. The GQDs and MoS₂ films are characterized by Raman and photoluminescence (PL) spectroscopies, along with atomic force microscopy. After outlining the fabrication of our 0D–2D heterostructure photodetectors comprising GQDs with bulk MoS₂ sheets, their photoresponse to the incoming radiation was measured. The hybrid GQD/MoS₂ heterostructure photodetector exhibits a high photoresponsivity R of more than 1200 A W^–1 at 0.64 mW/cm² at room temperature T. The T-dependent optoelectronic measurements revealed a peak R of ∼544 A W^–1 at 245 K, examined from 5.4 K up to 305 K with an incoming white light power density of 3.2 mW/cm². A tunable laser revealed the photocurrent to be maximal at lower wavelengths in the near ultraviolet (UV) over the 400–1100 nm spectral range, where the R of the hybrid GQDs/MoS₂ was ∼775 A W^–1, while a value of 2.33 × 10¹² Jones was computed for the detectivity D* at 400 nm. The external quantum efficiency was measured to be ∼99.8% at 650 nm, which increased to 241% when the wavelength of the incoming laser was reduced to 400 nm. Time-resolved measurements of the photocurrent for the hybrid devices resulted in a rise time τ_rise and a fall time τ_fall of ∼7 and ∼25 ms, respectively, at room T, which are 10× lower compared to previous reports. From our promising results, we conclude that the GQDs exhibit a sizable band gap upon optical excitation, where photocarriers are injected into the MoS₂ films, endowing the hybrids with long carrier lifetimes to enable efficient light absorption beyond the visible and into the near-UV regime. The GQD–MoS₂ structure is thus an enabling platform for high-performance photodetectors, optoelectronic circuits, and quantum devices.

中文翻译：

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半导体石墨烯量子点中集成2D MoS _2的光物理动力学，用于近紫外光增强

已经研究了零维（0D）石墨烯量子点（GQDs）和半导体二维（2D）MoS ₂的混合结构，它们显示出超越MoS ₂光电探测器的局限性的光电器件优异的性能，其中GQD扩展了光学吸收到近紫外线区域。GQD和MoS ₂薄膜的特征在于拉曼光谱和光致发光（PL）光谱，以及原子力显微镜。在概述了我们的0D–2D异质结构光电探测器（包括带有大量MoS ₂片的GQD）的制造后，测量了它们对入射辐射的光响应。混合GQD / MoS ₂异质结构光电探测器具有高光响应性在室温T下，在0.64 mW / cm ^2时，R大于1200 AW ^–1。所述Ť依赖性光电子测量表明峰值ř ~544 AW的^-1在245 K，从5.4ķ向上检查，以305 K的3.2毫瓦/平方厘米的进入的白光的功率密度²。可调激光器显示，在400-1100 nm光谱范围内，在近紫外（UV）的较低波长处，光电流最大，其中混合GQDs / MoS ₂的R为〜775 AW ^–1，而值为2.33 ×10 ¹² Jones被计算出探测灵敏度D*在400 nm处。在650 nm处测得的外部量子效率为〜99.8％，当入射激光的波长减小到400 nm时，外部量子效率增加到241％。光电流对混合设备的时间分辨的测量导致的上升时间τ_上升和下降时间τ_下降的~7和〜25毫秒，分别在室温Ť，10×下相比以前的报告它们。从我们有希望的结果中，我们得出结论，GQD在光激发时会显示出相当大的带隙，其中将光载流子注入MoS ₂薄膜中，使杂化体具有较长的载流子寿命，从而能够有效吸收可见光和近紫外光政权。GQD–MoS ₂ 因此，该结构是高性能光电探测器，光电电路和量子设备的使能平台。