Quantum Dot/Graphene Heterostructure Nanohybrid Photodetectors

Wu, Judy; Gong, Maogang; Schmitz, Russell C.; Liu, Bo

doi:10.1007/978-3-030-74270-6_5

Cited by 10 publications

(25 citation statements)

References 180 publications

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“…As shown in Figure g, this charge transfer is driven by the built-in electric field at the PbS QD/graphene interface due to the band-edge alignment. MPA ligands can also passivate the surface states on the QD surface reducing their charge-trapping effect, thus enhancing efficient charge transfer across the interface, which is the key to high responsivity and response speed Figure h shows a picture of the optical setup and Arduino ROIC used for characterization of the obtained nine-channel PbS QD/graphene nanohybrid sensor arrays.…”

Section: Resultsmentioning

confidence: 99%

“…At a chopper frequency of 55 Hz, the rise and fall times drop to 2.3 ms ± 0.5 ms and 5.6 ms ± 1.0 ms, respectively, as seen in Figure S2. It should be pointed out that the asymmetric dynamic response and the tails in both rise and fall are indicative of residual charge traps on the PbS QD surface and/or PbS QD/graphene interface . The charge traps are often associated to the QD surface states and the QD/graphene interface contaminated with various unintended molecules or chemical agents adsorbed to the interface .…”

Section: Resultsmentioning

confidence: 99%

“…In this work, 12 printing scans were used to obtain a PbS QD layer thickness of about 100 nm on Si substrates. Since the photoresponsivity and response speed both are determined by the efficiency of charge transfer across the QD/graphene interface, , controlling the interface is a critical step for high-performance QD/graphene photodetectors. For PbS QD/graphene photodetectors, a ligand-exchange process was developed to establish such a charge transfer across the QD/graphene interface.…”

Section: Methodsmentioning

confidence: 99%

“…The last step of charge transfer is driven by the built-in electric field at the QD/graphene interface, with one type of charge carrier transferred to graphene while the other oppositely charged carrier is trapped in the QDs. The exciton lifetime is much enhanced in QDs as compared to that in bulk semiconductors due to the quantum confinement . The trapped charge in QDs will generate a so-called photogating effect on graphene, which alters the electrical conductivity of the graphene channel as the photoresponse.…”

Section: Introductionmentioning

confidence: 99%

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Development of Broadband PbS Quantum Dot/Graphene Photodetector Arrays with High-Speed Readout Circuits for Flexible Imagers

Shultz

Liu

Gong

et al. 2022

ACS Appl. Nano Mater.

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Colloidal quantum dot (QD)/graphene nanohybrid heterostructures provide a promising scheme for quantum sensors as they take advantage of the strong quantum confinement in QDs with enhanced light−matter interaction, spectral tunability, suppressed phonon scattering, and extraordinary charge mobility in graphene at room temperature. Herein, we report development of a flexible, nine-channel PbS QD/graphene nanohybrid imaging array on polyethylene terephthalate using a facile process for device fabrication, signal acquisition, and processing. The PbS QD/graphene imaging array exhibited high and uniform photoresponse. At a 1.0 V bias, the highest responsivity was 9.56 × 10 3 −3.24 × 10 3 A/W for 400−1000 nm incident light [ultraviolet−visible−near-infrared (UV−vis−NIR)] with a power of 900 pW. In addition, the array has a consistent spectral response with bending down to a radius of curvature of a few millimeters. The demonstration of imaging at broadband wavelengths in the UV−vis− NIR range indicates that QD/graphene nanohybrids provide a viable approach for flexible photodetectors and imagers.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Development of Broadband PbS Quantum Dot/Graphene Photodetector Arrays with High-Speed Readout Circuits for Flexible Imagers

Shultz

Liu

Gong

et al. 2022

ACS Appl. Nano Mater.

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“…Hybrid plasmonic structures, while combining the properties of dielectric and plasmonic waveguides, are designed to achieve high light confinement without including high losses [16]. Experimental research has expanded to include the fabrication and study of QD-graphene nanostructures [10,17]. These structures can make a significant contribution to the formation of plasmonic waveguides.…”

Section: Introductionmentioning

confidence: 99%

Interaction between Graphene Nanoribbon and an Array of QDs: Introducing Nano Grating

2022

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In this work, the interaction between an array of QDs and Graphene nanoribbon is modeled using dipole–dipole interaction. Then, based on the presented model, we study the linear optical properties of the considered system and find that by changing the size, number, and type of quantum dots as well as how they are arranged, the optical properties can be controlled and the controllable grating plasmonic waveguides can be implemented. Therefore, we introduce different structures, compare them together and find that each of them can be useful based on their application in optical integrated circuits. The quantum dot arrays are located on a graphene nanoribbon with dimensions of 775 × 40 nm2. Applying electromagnetic waves with a wavelength of 1.55 µm causes polarization in the quantum dots and induces surface polarization on graphene. It is shown that, considering the large radius of the quantum dot, the induced polarization is increased, and ultimately the interaction with other quantum dots and graphene nanoribbon is stronger. Similarly, the distance between quantum dots and the number of QDs on Graphene nanoribbon are basic factors that affect the interaction between QDs and nanoribbon. Due to the polarization effect of these elements between each other, we see the creation of the effective grating refractive index in the plasmonic waveguide. This has many applications in quantum optical integrated circuits, nano-scale atomic lithography for nano-scale production, the adjustment coupling coefficient between waveguides, and the implementation of optical gates, reflectors, detectors, modulators, and others.

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Graphene/Quantum Dot Heterostructure Photodetectors: From Material to Performance

Zhang

Liu

Gong

et al. 2022

Advanced Optical Materials

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Owing to its high carrier mobility, electrical conductivity, and thermal/chemical stability, graphene is an ideal candidate material for photodetection. However, the weak light absorption of graphene significantly limits its practical applications in photodetectors. Quantum dots, with strong light-absorption capacity and well-adjustable band gap, are widely hybridized with graphene to realize wide-range and intense light absorption for effective photodetection. A detailed literature review on graphene/quantum dot heterostructure photodetectors is in urgent need to clearly point out the fundamentals, material synthesis methods, and performance engineering strategies. Here, first, the significance of graphene/quantum dot heterostructure photodetectors, from the mechanism to performance indicators, is systematically discussed. Second, different synthesis methodologies for the graphene/quantum dot heterostructure are overviewed. Additionally, the engineering strategies, including surface treatment, chemical doping, and size modification, to tune the photoelectric performance are critically commented. Finally, challenges and outlook for the development of graphene/quantum dot heterostructure photodetectors are pointed out.

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Quantum Dot/Graphene Heterostructure Nanohybrid Photodetectors

Cited by 10 publications

References 180 publications

Development of Broadband PbS Quantum Dot/Graphene Photodetector Arrays with High-Speed Readout Circuits for Flexible Imagers

Development of Broadband PbS Quantum Dot/Graphene Photodetector Arrays with High-Speed Readout Circuits for Flexible Imagers

Interaction between Graphene Nanoribbon and an Array of QDs: Introducing Nano Grating

Graphene/Quantum Dot Heterostructure Photodetectors: From Material to Performance

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