ACS Nano
·
2023
·
IF 17.1
Can Zou,Zixuan Zhao,Mingjun Xu,Xingfu Wang,Qing Liu,Kai Chen,Longfei He,Fangliang Gao,Shuti Li
To overcome the problem of minority carrier storage time in bipolar transistors, a hot electron transistor (HET) has been proposed. This device has the advantage of high working speed and some complex logic functions can be completed by using one component. Here, we demonstrate a mixed-dimensional HET composed of GaN/AlN microwires, graphene (Gr), and Si. The electrons between GaN/AlN are injected into graphene by an F-N tunneling mechanism to achieve high speed hot electrons, then cross graphene by ballistic transport, and are collected in a nearly lossless manner through a low-barrier Si. Therefore, the device shows a record DC gain of 16.2, a collection efficiency close to the limit of 99.9% based on the graphene hot electron transistor (GHET), an emitter current density of about 68.7 A/cm2, and a high on/off current ratio reaching ∼107. Meanwhile, the current saturation range is wide, beyond those of most GHETs. It has potential applications as a power amplifier.
研究领域:
电子学
·
材料科学
·
半导体物理
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DOI
PubMed
高影响因子
ANALYST
·
2024
·
IF 3.6
Zhiqi Gu,Hui Chang,Guo Yang,Boxuan Xu,Bin Miao,Jiadong Li
Vertical flow assay (VFA) is an effective point-of-care (POC) diagnostic tool for widespread applications. Nevertheless, the lack of multi-target detection and multi-signal readout capability still remain challenges. Herein, a brand new VFA scheme for multi-target saliva detection based on electronic-tags was proposed, where AlGaN/GaN HEMT sensors modified with different bio-receptors as electronic tags endowed the VFA a multi-target detection capability. In addition, the use of electronic tags instead of optical tags made that the VFA could simultaneously carry out direct multi-target readout, which ensure the effective POC diagnostic of saliva analysis. Moreover, by integrating a hydrophilically optimized micro-sieve, impurities like sticky filaments, epidermal cells and other large-scale charged particles in saliva were effectively screened, which enabled the direct detection of saliva by AlGaN/GaN HEMT sensors. Glucose, urea, and cortisol were selected to verified the feasibility of the multi-target e-VFA scheme, results displayed that the limit-of-detection (LOD) was as low as 100 aM. The linear response was demonstrated in the dynamic range of 100 aM - 100 μM, the specificity and long-term stability and the validity of the actual saliva test were also verified. These results demonstrated that the as-proposed e-VFA had potential application in saliva detection for multi-target simultaneous detection, and it is expected to achieve the real-time detection of more biological targets in saliva.
研究领域:
生物医学工程
·
诊断学
·
传感器技术
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DOI
PubMed
高影响因子
Materials Horizons
·
2022
·Vol. 9
·期 5
·1479-1488
·
IF 15.717
Can Zou,Qing Liu,Kai Chen,Fei Chen,Zixuan Zhao,Yunxuan Cao,Congcong Deng,Xingfu Wang,Xiaohang Li,Shaobin Zhan,Fangliang Gao,Shuti Li
Polarization-sensitive photodetectors are the core of optics applications and have been successfully demonstrated in photodetectors based on the newly-emerging metal-halide perovskites. However, achieving high polarization sensitivity is still extremely challenging. In addition, most of the previously reported photodetectors were concentrated on 1D lead-halide perovskites and 2D asymmetric intrinsic structure materials, but suffered from being external bias driven, lead-toxicity, poor stability and complex processes, severely limiting their practical applications. Here, we demonstrate a high-performance polarization-sensitive and stable polarization-sensitive UV photodetector based on a dendritic crystal lead-free metal-halide CsCu2I3/GaN heterostructure. By combining the anisotropic morphology and asymmetric intrinsic structure of CsCu2I3 dendrites with the isotropic material GaN film, a high specific surface area and built-in electric field are achieved, exhibiting an ultra-high polarization selectivity up to 28.7 and 102.8 under self-driving mode and −3 V bias, respectively. To our knowledge, such a high polarization selectivity has exceeded those of all of the reported perovskite-based devices, and is comparable to, or even superior to, those of the conventional 2D heterostructure materials. Interestingly, the unsealed device shows outstanding stability, and can be stored for over 2 months, and effectively maintained the performance even after repeated heating (373K)-cooling (300K) for different periods of time in ambient air, indicating a remarkable temperature tolerance and desired compatibility for applications under harsh conditions. Such excellent performance and simple method strongly show that the CsCu2I3/GaN heterojunction photodetector has great potential in practical applications with high polarization-sensitivity. This work provides a new insight into designing novel high-performance polarization-sensitive optoelectronic devices.
研究领域:
材料科学
·
光学工程
·
电子器件
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Xue-Xia Chen,Xu-Hua Xiao,Zhi-Feng Shi,Rui Du,Xin-Jian Li
Using silicon nanoporous pillar array (Si-NPA) as substrate, a kind of GaN/Si nanoheterostructure (GaN/Si-NPA) is prepared by depositing GaN nanocrystallites on Si-NPA with chemical vapor deposition method. The morphology characteristics and optical properties of GaN/Si-NPA are investigated systematically. Based on GaN/Si-NPA, a self-powered ultraviolet (UV) photodetector (PD) with device structure of ITO/GaN/Si-NPA/ sc -Si/Ag is constructed by depositing ITO on GaN layer and silver on single crystal silicon , respectively. At zero bias voltage without an external power supply, GaN/Si-NPA exhibits a responsivity of 0.072 mA/W, a high current on/off ratio of ∼10 4 (16 μW/cm 2 ) and fast response speeds of 39.98/40.10 ms under an UV light irradiation at 305 nm. The high performance of GaN/Si-NPA is attributed to the built-in electric field in the heterojunction , which is interpreted via building the energy-band diagrams. The results illustrate that GaN/Si-NPA might be a suitable material system for self-powered UV PDs.
研究领域:
材料科学
·
光子学
·
半导体物理
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产品关联
DOI
高影响因子
Analytical Methods
·
2024
·
IF 2.7
Guo Yang,Boxuan Xu,Hui Chang,Zhiqi Gu,Jiadong Li
The abundant bio-markers in saliva provide a new option for non-invasive testing. However, due to the presence of impurities in the saliva backgroud, most of the existing saliva testing methods rely on pre-processing, which limits the application of saliva testing as a convenient means of testing in daily life. Herein, a disposible-gate AlGaN/GaN high electron mobility transistor (HEMT) biosensor integrated with micro-sieve was intoduced to solve the problem that signal interference caused by charged impurities in saliva for HEMT based biosensors, where the micro-sieve was ultilized as a pre-treatment unit to remove large particles of impurities from saliva through size effect and thus greatly inproving the accuracy of detection. The experimental results showed that the HEMT based biosensor has has excellent linearity (R2 = 0.9977) and a high sensitivity of 6.552 µA·dec−1 for urea sensing from 1 fM to 100 mM in 0.1×PBS solution. When it comes to artificial saliva detection, compare to the HEMT sensor without micro-sieve (sensitivity = 3.07432μA·dec−1), the sensitivity of HEMT sensor integrated with micro-sieve had almost no change. Moreover, to verify that urea can be detected in actual saliva, urea is sensed directly in human saliva. The addition of the microsieve module provides a new way for biosensors to detect specific markers in saliva in real time, and the designed HEMT biosensor with microsieve function has a wide range of application potential in rapid saliva detection.
研究领域:
生物医学工程
·
电气工程
·
材料科学
·
分析化学
·
医疗器械
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产品关联
DOI
PubMed
高影响因子
Micromachines
·
2023
·Vol. 14
·期 3
·566
·
IF 3.4
Wenjun Huang,Xiangyu Miao,Zhaojun Liu
The optoelectronic effects of sidewall passivation on micro-light-emitting diodes (Micro-LEDs) were investigated using sol-gel chemical synthesis. Blue InGaN/GaN multi-quantum well (MQW) Micro-LEDs, ranging in size from 20 × 20 μm to 100 × 100 μm and with high EQE, were fabricated and distinguished by the passivation method used, including no passivation, sol-gel SiO2, and plasma-enhanced chemical vapor deposition (PECVD) SiO2. Impressively, the sol-gel method is advantageous in improving the optoelectronic performance of Micro-LEDs. The fabricated 20 × 20 μm Micro-LEDs showed an EQE of 27.7% with sol-gel passivation, which was a 14% improvement compared to devices without sidewall passivation. Sol-gel sidewall passivation allows Micro-LEDs to effectively achieve sharper edge emission, superior surface luminous uniformity, and intensity, providing the possibility for the fabrication of low-cost and high-efficiency Micro-LEDs.Keywords:sidewall passivation;sol-gel SiO2;GaN-based micro-light-emitting diodes (Micro-LEDs)
研究领域:
材料科学
·
光电子学
·
半导体器件
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DOI
PubMed
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Lixin Chen,Xiaorui Yu,Zhe Hua,Qing Liu,Vladimir An,Lizhi Feng,Jiaming Guo,Xinglai Zhang,Jing Li,Baodan Liu
Photoelectrochemical water splitting based on suitable catalysts has attracted wide attention as a promising strategy to utilize solar energy to produce clean and renewable hydrogen fuel. Herein, we reported cobalt phosphate-modified (GaN)1–x(ZnO)x/GaN nanowire arrays on a high-temperature conductive GaN substrate toward enhanced photoelectrochemical water splitting by a facile two-step Au-assisted chemical vapor deposition method. The highly conductive Si-doped GaN substrate is designed to serve as a current collector and epitaxial substrate to grow GaN nanowires at high temperature. Meanwhile, high density of branched (GaN)1–x(ZnO)x nanowires with a tunable band gap, strong visible-light absorption, and high catalytic activity is deposited on the surface of GaN nanowires to act as active components to harvest light toward the oxygen evolution reaction. Such multi-junction heterostructures effectively enhance wide spectral utilization and light absorption and simultaneously accelerate the separation of electrons and holes and the transfer of photogenerated electrons from (GaN)1–x(ZnO)x nanowires to the GaN substrate collector and Pt electrode. The photocurrent density of the (GaN)1–x(ZnO)x/GaN nanowire array photoanode can reach 37.5 μA cm–2 at 1.23 V vs reversible hydrogen electrode and could be further enhanced to 186 μA cm–2 by modifying the cobalt phosphate cocatalyst, showing promising potential in clean hydrogen production.
研究领域:
材料科学
·
纳米技术
·
可再生能源
·
光电化学
✓ 已验证
DOI
高影响因子
NANO LETTERS
·
2017
·
IF 12.712
Baodan Liu,Wenjin Yang,Jing Li,Xinglai Zhang,Pingjuan Niu,Xin Jiang
Crystalline GaN nanosheets hold great challenge in growth and promising application in optoelectronic nanodevices. In this work, we reported an accessible template approach toward the rational synthesis of GaN nanosheets through the nitridation of metastable γ-Ga2O3 nanosheets synthesized from a hydrothermal reaction. The cubic γ-Ga2O3 nanosheets with smooth surface and decent crystallinity can be directly converted into hexagonal GaN nanosheets with similar morphology framework and comparable crystal quality in NH3 at 850 °C. UV–vis spectrum measurement reveals that the GaN nanosheets show a band gap of 3.30 eV with strong visible absorption in the range of 370–500 nm. The template synthetic strategy proposed in this work will open up more opportunities for the achievement of a variety of sheetlike nanostructures that can not be obtained through conventional routines and will undoubtedly further promote the fundamental research of newly emerging sheetlike nanostructures and nanotechnology.
研究领域:
材料科学
·
纳米技术
·
光电子学
·
无机化学
✓ 已验证
DOI
高影响因子
PLASMA CHEMISTRY AND PLASMA PROCESSING
·
2024
·
IF 2.6
Gang Yonggang,Long Yanhui,Wang Kaiyi,Zhang Yilin,Ren Xuping,Zhang Hao,Li Xiaodong
Recently, direct non-oxidative conversion of methane (NOCM) into hydrogen and light hydrocarbons has garnered considerable attention. In our work, we employed a dielectric barrier discharge (DBD) plasma over a GaN/SBA15 catalyst for NOCM. Adding catalyst to plasma remarkably promotes the conversion of CH 4 , resulting in a significant improvement, for instance, from 27.8 to 39.2%. A systematic investigation of plasma performance at different discharge powers with and without catalyst was conducted. In the case of plasma + 15wt% GaN/SBA15, CH 4 conversion reaches an impressive 79.4%. However, it exhibits the lowest selectivity of 14.4% for C 2 +, while achieving the highest selectivity for hydrogen at 48.9%. Several characterization methods, including XRD, SEM, BET, XPS, and TPO-MS, were used to study the mechanism of the reaction. Plasma electrons and ions can effectively interact with activated CH3 radicals, promoting their adsorption onto Ga sites on the catalyst surface. Simultaneously, hydrogen atoms adsorb onto neighboring N atoms, rapidly delocalizing to produce H 2 , and the delocalization of hydrogen atoms in C species leads to the formation of species like CxHy. This study highlights the potential of plasma catalysis in significantly improving CH 4 conversion at lower temperatures and atmospheric pressure.
研究领域:
化学工程
·
能源科学
·
催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2024
·Vol. 39
·期 4
·814-818
·
IF 1.3
Wang Peng,Zhang Binbin,Liu Xiaofei,Zhang Xin,Tu Rong,Zhang Song,Li Baowen
It remains a big challenge to synthesize two-dimensional (2D) GaN material for applications in power nanodevices. Traditional synthetic methods require complex equipment and processes and time consuming. Here, we reported a two-step route to prepare polycrystalline 2D GaN film. The amorphous ultrathin Ga 2 O 3 film was first exfoliated from the surface of liquid gallium. In a vapor phase reaction, 2D Ga 2 O 3 film was then converted into 2D GaN film while maintaining the 2D morphology. Raman and high-resolution transmission electron microscope (HRTEM) analysis implies the successful synthesis of wurtzite-type GaN ultrathin film. This simple strategy proposed in this work will provide more opportunities for applications of GaN ultrathin film in many devices.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL REVIEW B
·
2023
·Vol. 107
·期 8
·085304
·
IF 3.7
Weiqing Tang,Zongnan Zhang,Hao Zeng,Yaping Wu,Zhiming Wu,Xu Li,Chunmiao Zhang,Junyong Kang
Controlling over the electronic structure of two-dimensional (2D) semiconductors is crucial to unlock their full potential in the applications in future nanodevices. Here, we demonstrate a layer-dependent dielectric modulation of electronic structures in multilayer ${\mathrm{WS}}_{2}/\mathrm{GaN}$ heterostructures. The results investigated by means of in situ scanning tunneling microscopy/spectroscopy and photoluminescence spectroscopy show that the fluctuations of the dielectric environment induced by local corrugation of the GaN surface dramatically tune the band structure of monolayer ${\mathrm{WS}}_{2}$ with a large downshift of the valence band maximum by about 1.12 eV. Under the shielding effect of the first-layer ${\mathrm{WS}}_{2}$, the dielectric environment shows a weak modulation effect on the second-layer, and even has negligible influence on the third- and fourth-layer ${\mathrm{WS}}_{2}$. The relationship between dielectric environment and interfacial distance is further simulated through first-principles calculations. The electrostatic potential energy, differential charge densities, and charge transfer of the ${\mathrm{WS}}_{2}/\mathrm{GaN}$ heterostructure under different interfacial distances reveal that the differences of charge redistributions between the ${\mathrm{WS}}_{2}/\mathrm{GaN}$ interface and ${\mathrm{WS}}_{2}$ interlayer are responsible for the layer-dependent dielectric modulation. This work offers some references for the design and fabrication of novel 2D optoelectronic devices.
✓ 已验证
DOI
高影响因子
Nanoscale
·
2024
·
IF 5.8
Yong Wang,Shaopeng Wang,Yu Zhang,Zixuan Cheng,Dingyi Yang,Yongmei Wang,Tingting Wang,Liang Cheng,Yizhang Wu,Yue Hao
Gallium nitride (GaN) exhibits various potential applications in optics and optoelectronics due to its outstanding physical characteristics, including a wide direct bandgap, strong deep-ultraviolet emission, and excellent electron transport properties. However, research on the piezoelectric and related properties of GaN nanosheets are scarce, as previous small-scale GaN investigations have mainly concentrated on nanowires and nanotubes. Here, we report a strategy for growing 2D GaN nanosheets using chemical vapor deposition on Ga/W liquid-phase substrates. Additionally, utilizing scanning probe techniques, it has been observed that 700 nm-thick GaN nanosheets demonstrate a piezoelectric constant of deff33 = 1.53 ± 0.21 pm V−1 and possess the capability to effectively modulate the Schottky barrier. The piezoelectric characteristics of 2D GaN are offering new options for innovative applications in various fields, including energy harvesting, electronics, sensing, and communications.
研究领域:
材料科学
·
物理学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）