Precisely Controlled Ultrastrong Photoinduced Doping at Graphene–Heterostructures Assisted by Trap‐State‐Mediated Charge Transfer

Ho, Po Hsun; Chen, Chun Hsiang; Shih, Fu Yu; Chang, Young‐Chae; Li, Shao Sian; Wang, Wei Hua; Shih, Ming‐Chieh; Chen, Wei Ting; Chiu, Ya-Ping; Li, Min Ken; Shih, Yi Siang; Chen, Chun-Wei

doi:10.1002/adma.201503592

Cited by 39 publications

(52 citation statements)

References 30 publications

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“…Consistently with the recent reports on UV light induced graphene doping 23, 26 , the permanent change of resistivity upon initial X-ray irradiation can be explained by an accumulation of positive charge within the gate oxide, which via capacitance coupling induces negative graphene doping (Fig. 2b).…”

Section: Resultssupporting

confidence: 90%

“…Further measurements when the X-ray source remains switched off do not show any change in the BG trace even after several hours. If the device was taken out and its BG traces measured, the device returned to the pristine state (V BG = +17 V) only after a 24-hour long exposure of the sample to ambient conditions, which is consistent with the UV/Vis irradiation induced doping effect reported to be stable under vacuum at least for several days 24, 26, 28 .…”

Section: Resultssupporting

confidence: 81%

“…Donor-like defects are neutral when they are occupied with electron and can be positively charged when one electron is released (or, equivalently, hole captured). These defect sites can be directly photoexcited to create charged defects () 23, 25, 26, 30 or ionized by capturing diffusing holes () 32 . This results in the build-up of the net positive charge bound in the gate oxide.…”

Section: Resultsmentioning

confidence: 99%

“…The effect of charged impurities and adsorbates is even more pronounced in graphene devices 17, 18 . Recently, the photo-induced doping of graphene has been realized by visible or UV radiation exposure of GFETs 19–26 . Here, two distinct groups of GFET devices were introduced: in the first group the charges excited within the photoabsorbing medium (e.g., MoS 2 , Bi 2 Te 3 , nanoparticles, and plasmonic antennas) are transferred to graphene appearing as an increase of the graphene DC conductivity 19–22 .…”

Section: Introductionmentioning

confidence: 99%

“…Within the second group the UV/Vis radiation ionize donor-like traps leaving the gate dielectric positively charged. This charge acts as a positive gate: it increases the electron concentration in graphene by capacitive coupling 23–26 . In contrast to direct graphene doping from adsorbed species causing also a decrease of carrier mobility 27 , the major advantage of “remote gating” is its minimal impact on the charge carrier mobility 24, 26, 28 .…”

Section: Introductionmentioning

confidence: 99%

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X-ray induced electrostatic graphene doping via defect charging in gate dielectric

Procházka

Mareček

Lišková

et al. 2017

Sci Rep

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Graphene field effect transistors are becoming an integral part of advanced devices. Hence, the advanced strategies for both characterization and tuning of graphene properties are required. Here we show that the X-ray irradiation at the zero applied gate voltage causes very strong negative doping of graphene, which is explained by X-ray radiation induced charging of defects in the gate dielectric. The induced charge can be neutralized and compensated if the graphene device is irradiated by X-rays at a negative gate voltage. Here the charge neutrality point shifts back to zero voltage. The observed phenomenon has strong implications for interpretation of X-ray based measurements of graphene devices as it renders them to significantly altered state. Our results also form a basis for remote X-ray tuning of graphene transport properties and X-ray sensors comprising the graphene/oxide interface as an active layer.

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Section: Resultssupporting

confidence: 90%

Section: Resultssupporting

confidence: 81%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

X-ray induced electrostatic graphene doping via defect charging in gate dielectric

Procházka

Mareček

Lišková

et al. 2017

Sci Rep

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Printable and Flexible Phototransistors Based on Blend of Organic Semiconductor and Biopolymer

Huang

Cevher

et al. 2017

Adv Funct Materials

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Printable and flexible organic phototransistors (OPTs) make comprehensive requirements for the organic semiconductors (OSCs), including high photosensitivity, decent transistor characteristics, appropriate solution viscosity, and good film flexibility. It has been challenging to obtain such semiconductors. Here, we demonstrated that by taking advantage of the interfacial charge effect, printable and flexible OPTs with high performance can be successfully fabricated through simply blending common OSCs with polymers. Using 2,7‐dioctyl[1]benzothieno[3,2‐b][1]benzothiophene and an insulating biopolymer polylactide, OPTs with blended and layered structure are both fabricated and investigated. The photoresponses of the OPTs can be modulated by gate voltage over 1000 times, and their responsivities are measured up to 400 A W−1. As compared to the layered OPTs, the blended ones exhibit higher photocurrent to dark current ratio (up to 105) and better light detection limit (lower than 0.02 mW cm−2). The improvements are attributed to larger interfacial area and more intensive charge trapping effect. The flexible OPTs are further fabricated by inkjet printing the blended solution. This work presents OPTs with comprehensive advantages including low cost, enhanced photosensitivity, great flexibility, and printability, which are realized by simply blending common OSC with polymer, and thus provide an inspiration for the design of novel organic electronics.

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Epitaxial Ultrathin Organic Crystals on Graphene for High‐Efficiency Phototransistors

et al. 2016

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Epitaxially grown ultrathin organic semiconductors on graphene show great promise as highly efficient phototransistors. The devices exhibit a strong photoresponse down to the limit of a monolayer organic crystal, with a photoresponsivity higher than 10(4) A W(-1) and a photoconductive gain over 10(8) . The excellent performance is attributed to the high quality of the organic crystal and interface, a unique feature of van der Waals epitaxy.

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Precisely Controlled Ultrastrong Photoinduced Doping at Graphene–Heterostructures Assisted by Trap‐State‐Mediated Charge Transfer

Cited by 39 publications

References 30 publications

X-ray induced electrostatic graphene doping via defect charging in gate dielectric

X-ray induced electrostatic graphene doping via defect charging in gate dielectric

Printable and Flexible Phototransistors Based on Blend of Organic Semiconductor and Biopolymer

Epitaxial Ultrathin Organic Crystals on Graphene for High‐Efficiency Phototransistors

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