Fast-response solar-blind ultraviolet photodetector with a graphene/β-Ga2O3/graphene hybrid structure

Ai, Meilin; Guo, Daoyou; Qu, Yingyu; Cui, Wei; Wu, Zhenping; Li, Peigang; Li, Linghong

doi:10.1016/j.jallcom.2016.09.087

Cited by 85 publications

(68 citation statements)

References 27 publications

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“…In addition to graphene/Ga 2 O 3 /GaN heterojunction, the vertical nanowire array itself plays a very important role in the high performance of the devices. Because of the high surface‐to‐volume ratio of the nanowires, trapping at surface states drastically affects the transport and photoconduction properties of nanowires, which can further enhance the photoconductive gain . In the dark, oxygen molecules are adsorbed on the nanowire surface and capture the free electrons in the Ga 2 O 3 /GaN semiconductor [

{normalO}_{2} + {normale}^{-} \to {normalO}_{2}^{-}

], forming a low‐conductivity depletion layer near the surface.…”

Section: Resultsmentioning

confidence: 99%

Broadband Ultraviolet Photodetector Based on Vertical Ga₂O₃/GaN Nanowire Array with High Responsivity

Zhang

Ding

et al. 2019

Advanced Optical Materials

103

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attracted significant attention, which has a vast and growing number of military and civilian applications such as fire detection, missile interception, ozone hole monitoring, bioaerosol detection, astronomical imaging, and so on. [1][2][3] As the continuous improvement of devices integration, environment complexity, and interference technology, BUV photodetectors can effectively reduce false alarm rates in early warning, searching, and tracking systems, to improve the accuracy and versatility of detection systems in various situations. Many heterojunction structures based on wide-band-gap semiconductors have been reported to achieve the BUV photodetectors such as AlGaN/GaN, MgZnO/ZnO, and Ga 2 O 3 /GaN heterojunction. [4][5][6][7][8][9][10] However, AlGaN/GaN heterojunction has a high conduction band discontinuity which impedes the flow of photogenerated electrons and reduces the performance of photodetectors. [11] And high Mg-content MgZnO with high crystal quality is difficult to achieve by epitaxial growth due to the phase segregation in single wurtzite phase MgZnO. [12] β-Ga 2 O 3 with an ultrawide bandage of 4.9 eV is considered as a promising candidate for UV detection. [13,14] It has great thermal and chemical stability, determining its possibility of working at high temperatures and strong radiations. Moreover, there is a small lattice mismatch and a low conduction band offset at the interface between Ga 2 O 3 and GaN. These characteristics mean that Ga 2 O 3 /GaN heterojunction could be a potential for BUV photodetectors. Kalra et al. [6] demonstrated epitaxial β-Ga 2 O 3 /GaN-based vertical metal-heterojunctionmetal multiband UV photodetectors with the responsivity (R) of 3.7 A W −1 at 256 and 365 nm. For saving energy and broadening the application prospects of UV photodetectors, Guo et al. [15] fabricated a super-high-performance self-powered UV photodetector based on the GaN/Sn:Ga 2 O 3 p-n junction generated by depositing a Sn-doped n-type Ga 2 O 3 thin film onto a p-type GaN thick film. The responsivity at 254 nm reached up to 3.05 A W −1 without consuming external power. Lin et al. [16] used graphene as the transparent conductive layer to form graphene/β-Ga 2 O 3 /GaN heterojunction. With the help of largearea transparent electrode, a typical "sandwich" structure UV photodetector with low dark current density (1.25 × 10 −8 A cm −2 ) and high sensitivity (12.8 A W −1 ) was successfully assembled. Broadband ultraviolet (BUV) photodetectors responding to the multiband spectrum can effectively reduce false alarm rates and improve the accuracy and versatility of detection systems in various situations. A high-responsivityBUV photodetector based on vertical Ga 2 O 3 /GaN nanowire array is proposed and demonstrated. Ga 2 O 3 /GaN nanowires are obtained by partially thermally oxidizing GaN nanowires grown by molecular beam epitaxy and used to combine with a monolayer graphene film to form graphene/Ga 2 O 3 /GaN heterojunction. Moreover, the oxidation mechanism of GaN nanowires is further investigated by ...

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{normalO}_{2} + {normale}^{-} \to {normalO}_{2}^{-}

], forming a low‐conductivity depletion layer near the surface.…”

Section: Resultsmentioning

confidence: 99%

Broadband Ultraviolet Photodetector Based on Vertical Ga₂O₃/GaN Nanowire Array with High Responsivity

Zhang

Ding

et al. 2019

Advanced Optical Materials

103

View full text Add to dashboard Cite

show abstract

“…Different types of photodetectors based on Ga2O3 have been demonstrated. This includes metal-semiconductor-metal structures [15,17], Schottky barrier diodes [21], diamond/Ga2O3 heterojunctions [4], and graphene/Ga2O3/graphene hybrid structures [22]. Field-effect-transistors (FETs) are also often used as photodetectors due to their abilities of controlling the off current by gate bias.…”

Section: Introductionmentioning

confidence: 99%

Ga₂O₃ Field-Effect-Transistor-Based Solar-Blind Photodetector With Fast Response and High Photo-to-Dark Current Ratio

Liu

Liang

et al. 2018

IEEE Electron Device Lett.

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A high performance solar-blind photodetector based on Cr-doped gallium oxide (Ga2O3) has been fabricated. A 140nm-thick Ga2O3 layer was mechanically exfoliated from bulk crystal. The photodetector was based on a field effect transistor structure, which showed a very high photo-to-dark current ratio larger than 10 6 and excellent current saturation. When the photodetector was tested with a 254 nm ultraviolet light, the ratio of drain current with and without the UV light reached nearly six orders of magnitude. The dark current was as low as 5 pA. Furthermore, the current rise time and decay time were both about 25 ms. High responsivity of 4.79 × 10 5 A/W and external quantum efficiency of 2.34 × 10 6 also have been achieved at the same time. Index Terms-gallium oxide (Ga2O3), filed-effect-transistor (FET), solar-blind photodetector

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“…Recently, a lot of attention has been focused on the integration of 2D layered materials with other 2D or 3D bulk semiconductor materials to form heterostructures due to the improved functionality of electronic and optoelectronic devices . The 2D material‐based devices can have a revolutionizing impact on technology covering from vacuum photodetection and photovoltaics to optical modulators and high speed data communication . Predominantly through vertical transport of photogenerated carriers, the hybrid structures allow us to overcome the inherent persistent photoconductivity (PPC), where photocurrent of the host material generally persists for a long duration even after the illumination is removed, generally observed in the compound III‐nitride semiconductor materials .…”

Section: Introductionmentioning

confidence: 99%

Long‐Term, High‐Voltage, and High‐Temperature Stable Dual‐Mode, Low Dark Current Broadband Ultraviolet Photodetector Based on Solution‐Cast r‐GO on MBE‐Grown Highly Resistive GaN

Prakash

Kumar

Singh

et al. 2019

Advanced Optical Materials

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materials to form heterostructures due to the improved functionality of electronic and optoelectronic devices. [1][2][3][4][5][6] The 2D material-based devices can have a revolutionizing impact on technology covering from vacuum photodetection and photovoltaics to optical modulators and high speed data communication. [7][8][9][10][11][12][13][14][15][16] Predominantly through vertical transport of photogenerated carriers, the hybrid structures allow us to overcome the inherent persistent photoconductivity (PPC), where photocurrent of the host material generally persists for a long duration even after the illumination is removed, generally observed in the compound III-nitride semiconductor materials. [17][18][19][20][21] Usually PPC occurs due to the presence of donor and acceptor states closer to the conduction band minimum (CBM) and valence band maximum (VBM), which provides a large number of electron and hole trap states in the host material, respectively. Alternatively, with an introduction of intrinsic semiconductor materials, the PPC could be reduced as the donor and acceptor states show a shift from the CBM and VBM edges toward the midgap positions, which facilitate fast recombination time in comparison to the transit time of photo generated carriers through host materials. This has resulted in high speed operation in photoconductive mode. [22] In particular, GaN integrated with reduced-graphene oxide (r-GO) is a promising heterostructure for achieving improved device characteristics such as low dark current, high spectral responsivity, and high response speed. [17] 2D r-GO makes an optically active heterojunction with GaN. The emphasis so far has been given on r-GO/GaN heterostructure operating in the photovoltaic mode where the photogenerated carriers are swiftly swept across the depletion region predominantly via vertical transport. However, in the photoconductive mode operation, where the photogenerated carriers traverse across the host materials under the influence of an external bias exceeding the built-in-field of the heterostructure device, suffers either from high leakage current and/or PPC due to inherently negatively charged defects rich GaN. [23] The intentional/unintentional doping of suitable species can cause compensation of free New generation of hybrid photodetectors may provide the optimal solution for compact, highly sensitive, durable, and reliable broadband ultraviolet (BUV) sensors. A high-performance dual-mode BUV photodetector based on melding of highly resistive GaN and reduced graphene oxide is reported. Under zero bias, the device exhibits a sub-picoampere dark current, high light-to-dark current (I Light /I Dark ) ratio of ≈3.8 × 10 3 and high BUV-visible rejection ratio (≈1.8 × 10 2 ) with fast rise and fall times. The photodetector displays remarkable stability when subject to extreme operating conditions. The photoresponse of the detector shows a dark current of ≈2.41 nA at ± 200 V bias, I Light /I Dark ratio of ≈200 and high BUV-vis rejection ratio (≈7 × 10 2 ). The response ...

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Fast-response solar-blind ultraviolet photodetector with a graphene/β-Ga2O3/graphene hybrid structure

Cited by 85 publications

References 27 publications

Broadband Ultraviolet Photodetector Based on Vertical Ga₂O₃/GaN Nanowire Array with High Responsivity

Broadband Ultraviolet Photodetector Based on Vertical Ga₂O₃/GaN Nanowire Array with High Responsivity

Ga₂O₃ Field-Effect-Transistor-Based Solar-Blind Photodetector With Fast Response and High Photo-to-Dark Current Ratio

Long‐Term, High‐Voltage, and High‐Temperature Stable Dual‐Mode, Low Dark Current Broadband Ultraviolet Photodetector Based on Solution‐Cast r‐GO on MBE‐Grown Highly Resistive GaN

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Fast-response solar-blind ultraviolet photodetector with a graphene/β-Ga2O3/graphene hybrid structure

Cited by 85 publications

References 27 publications

Broadband Ultraviolet Photodetector Based on Vertical Ga2O3/GaN Nanowire Array with High Responsivity

Broadband Ultraviolet Photodetector Based on Vertical Ga2O3/GaN Nanowire Array with High Responsivity

Ga2O3 Field-Effect-Transistor-Based Solar-Blind Photodetector With Fast Response and High Photo-to-Dark Current Ratio

Long‐Term, High‐Voltage, and High‐Temperature Stable Dual‐Mode, Low Dark Current Broadband Ultraviolet Photodetector Based on Solution‐Cast r‐GO on MBE‐Grown Highly Resistive GaN

Contact Info

Product

Resources

About

Broadband Ultraviolet Photodetector Based on Vertical Ga₂O₃/GaN Nanowire Array with High Responsivity

Broadband Ultraviolet Photodetector Based on Vertical Ga₂O₃/GaN Nanowire Array with High Responsivity

Ga₂O₃ Field-Effect-Transistor-Based Solar-Blind Photodetector With Fast Response and High Photo-to-Dark Current Ratio