Graphene/Si‐Quantum‐Dot Heterojunction Diodes Showing High Photosensitivity Compatible with Quantum Confinement Effect

Shin, Dong Hwa; Kim, Sung Hoon; Kim, Jong Min; Jang, Chan Wook; Kim, Woo Jung; Lee, Kyeong Won; Kim, Jungkil; Oh, Si Duck; Lee, Dae Hun; Kang, Soo Seok; Kim, Chang Oh; Choi, Suk‐Ho; Kim, Kyung Joong

doi:10.1002/adma.201500040

Cited by 57 publications

(31 citation statements)

References 38 publications

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“…Figure 6), assuming the same sensing mechanism as previously reported for a graphenesemiconductor hybrid phototransistor. [9][10][11][12][13] By contrast, a high photoresponse was observed with visible light illumination, suggesting a new sensing mechanism in our phototransistor. Figure 1b shows the photocurrent (after dark current subtraction) of the as-prepared AgX-G photodetectors at room temperature under chopped light illumination (white light illumination with a power of~54.9 nW) at a 1-V source-drain voltage (V SD ) and a 0-V back-gate voltage (V G ).…”

Section: Photodetector Design Device Fabrication and Temporal Photormentioning

confidence: 75%

“…By contrast, graphene hybrid phototransistors [4][5][6][7][8] provide high photoresponsivity by incorporating a layer of light absorbing material, such as a layer of semiconducting quantum dots (QDs), [9][10][11][12][13] which is in contact with the graphene. Upon illumination, the photoexcited carriers in the QDs can be injected into graphene while the charged QDs layer can modulate the conductance of graphene by capacitive coupling.…”

Section: Introductionmentioning

confidence: 99%

“…9 Since the photon is absorbed by the incorporated light absorbing material, the spectral response of the graphene hybrid phototransistor seems to be fundamentally limited by the bandgap of the integrated materials as shown in previous studies. [5][6][7][8][9][10][11][12] However, the internal photoemission from graphene in the graphene-semiconductor hybrid structure provides an alternative method to realizing broadband photo sensing. [14][15][16] In this hybrid structure, the photocurrent is generated as the photoexcited hot electron in graphene is injected into the conduction band of the adjacent semiconductor.…”

Section: Introductionmentioning

confidence: 99%

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Electrochemical half-reaction-assisted sub-bandgap photon sensing in a graphene hybrid phsotodetector

et al. 2017

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The photogating effect has been previously utilized to realize ultra-high photoresponsivity in a semiconductor-graphene hybrid photodetector. However, the spectral response of the graphene hybrid photodetector was limited by the bandgap of the incorporated semiconductor, which partially compromised the broadband absorption of graphene. Here, we show that this limitation can be overcome in principle by harnessing the electron-accepting ability of the electrochemical half-reaction. In our new graphene phototransistor, the electrochemical half-reaction serves as an effective reversible electron reservoir to accept the photoexcited hot electron from graphene, which promotes the sub-bandgap photosensitivity in a silver chloride (AgCl)-graphene photodetector. The photoconductive gain of~3 × 10 9 electrons per photon in the AgCl-graphene hybrid is favored by the long lifetime of photoexcited carriers in the chemically reversible redox couple of AgCl/Ag 0 , enabling a significant visible light (400-600 nm) responsivity that is far beyond the band-edge absorption of AgCl. This work not only presents a new strategy to achieve an electrically tunable sub-bandgap photoresponse in semiconductor-graphene heterostructures but also provides opportunities for utilizing the electrochemical half reaction in other two-dimensional systems and optoelectronic devices.

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Section: Photodetector Design Device Fabrication and Temporal Photormentioning

confidence: 75%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Electrochemical half-reaction-assisted sub-bandgap photon sensing in a graphene hybrid phsotodetector

et al. 2017

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“…For large responsivity, graphene should be used as a contact, not as a photo-active element. Several studies [53,57,[76][77][78][79][80][81][82] on the photodetecting potential of graphene heterojunctions have shown that careful selection of materials allows for significant enhancement of responsivity by up to $10 orders of magnitude (see Fig. 2b).…”

Section: Visible and Ultravioletmentioning

confidence: 99%

Radiation effects on two-dimensional materials

Walker

Shi

Cruz‐Silva

et al. 2016

Phys. Status Solidi A

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The effects of electromagnetic and particle irradiation on two‐dimensional materials (2DMs) are discussed in this review. Radiation creates defects that impact the structure and electronic performance of materials. Determining the impact of these defects is important for developing 2DM‐based devices for use in high‐radiation environments, such as space or nuclear reactors. As such, most experimental studies have been focused on determining total ionizing dose damage to 2DMs and devices. Total dose experiments using X‐rays, gamma rays, electrons, protons, and heavy ions are summarized in this review. We briefly discuss the possibility of investigating single event effects in 2DMs based on initial ion beam irradiation experiments and the development of 2DM‐based integrated circuits. Additionally, beneficial uses of irradiation such as ion implantation to dope materials or electron‐beam and helium‐beam etching to shape materials have begun to be used on 2DMs and are reviewed as well. For non‐ionizing radiation, such as low‐energy photons, we review the literature on 2DM‐based photo‐detection from terahertz to UV. The majority of photo‐detecting devices operate in the visible and UV range, and for this reason they are the focus of this review. However, we review the progress in developing 2DMs for detecting infrared and terahertz radiation.

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“…Silicon (Si) nanostructures are attracting considerable attention for a wide range of applications1, 2, 3, 4, 5, 6 due to their fascinating and highly complex properties 7, 8, 9. For instance, efficient photoluminescence (PL) from crystalline Si quantum dots (i.e., with diameter less than ≈5 nm) has been reported, which encourages their applications in optoelectronic devices such as light‐emitting diodes10 or in biomedical applications as fluorescent tags 11.…”

mentioning

confidence: 99%

The Interplay of Quantum Confinement and Hydrogenation in Amorphous Silicon Quantum Dots

et al. 2015

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Hydrogenation in amorphous silicon quantum dots (QDs) has a dramatic impact on the corresponding optical properties and band energy structure, leading to a quantum‐confined composite material with unique characteristics. The synthesis of a‐Si:H QDs is demonstrated with an atmospheric‐pressure plasma process, which allows for accurate control of a highly chemically reactive non‐equilibrium environment with temperatures well below the crystallization temperature of Si QDs.

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Graphene/Si‐Quantum‐Dot Heterojunction Diodes Showing High Photosensitivity Compatible with Quantum Confinement Effect

Cited by 57 publications

References 38 publications

Electrochemical half-reaction-assisted sub-bandgap photon sensing in a graphene hybrid phsotodetector

Electrochemical half-reaction-assisted sub-bandgap photon sensing in a graphene hybrid phsotodetector

Radiation effects on two-dimensional materials

The Interplay of Quantum Confinement and Hydrogenation in Amorphous Silicon Quantum Dots

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