APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Mohammadreza Rostami,Biao Yang,Felix Haag,Francesco Allegretti,Lifeng Chi,Martin Stutzmann,Johannes V. Barth
Gallium nitride (GaN), a wide bandgap semiconductor with absorption and emission in the ultraviolet/visible range, is proposed as an alternative to metallic surfaces for assembling organic molecular structures aiming at optoelectronic applications. However, the formation of a persistent surface oxide layer in air considerably limits the use of GaN for well-defined interfaces. In this work, we have investigated, characterized and processed n-type free-standing c-plane hexagonal wurtzite GaN crystals grown by hydride vapor phase epitaxy and ammonothermal growth methods. Surface cleaning and full removal of the oxide layer on GaN surfaces could be reproducibly achieved via sputtering and annealing cycles, as evidenced by X-ray photoelectron spectroscopy and low-energy electron diffraction. Scanning tunneling microscopy, however, indicated substantial roughening of the GaN surface and the formation of unwanted Ga-rich islands and clusters. Although ammonia (NH 3 ) and bromine (Br) treatments compensated the N/Ga atoms ratio reduced by sputtering, the surface morphology remained rough, exhibiting randomly shaped and distributed hillocks. In addition, we studied the effect of electron bombardment on the surface quality of GaN during NH 3 annealing, on-surface debromination and polymerization of 1,3,5-tris(4-bromophenyl) benzene on GaN, and the removal of Ga atoms by Br atoms during the desorption.
研究领域:
材料科学
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表面科学
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DOI
高影响因子
Advanced Science
·
2022
·Vol. 9
·期 22
·2201844
·
IF 17.521
Zong-Tao Li,Hong-Wei Zhang,Jia-Sheng Li,Kai Cao,Ziming Chen,Liang Xu,Xin-Rui Ding,Bin-Hai Yu,Yong Tang,Jian-Zhen Ou,Hao-Chung Kuo,Hin-Lap Yip
Tandem structures with different subpixels are promising for perovskite-based multicolor electroluminescence (EL) devices in ultra-high-resolution full-color displays; however, realizing excellent luminance- and color-independent tunability considering the low brightness and stability of blue perovskite light-emitting diodes (PeLEDs) remains a challenge. Herein, a bright and stable blue gallium nitride (GaN) LED is utilized for vertical integration with a green MAPbBr 3 PeLED, successfully achieving a Pe-GaN tandem LED with independently tunable luminance and color. The electronic and photonic co-excitation (EPCE) effect is found to suppress the radiative recombination and current injection of PeLEDs, leading to degraded luminance and current efficiency under direct current modulation. Accordingly, the pulse-width modulation is introduced to the tandem device with a negligible EPCE effect, and the average hybrid current efficiency is significantly improved by 139.5%, finally achieving a record tunable luminance (average tuning range of 16631 cd m −2 at an arbitrary color from blue to green) for perovskite-based multi-color LEDs. The reported excellent independent tunability can be the starting point for perovskite-based multicolor EL devices, enabling the combination with matured semiconductor technologies to facilitate their commercialization in advanced display applications with ultra-high resolution.
研究领域:
材料科学
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光电技术
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显示技术
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DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 18
·3238
·
IF 5.719
Long Xu,Yuehan Cao,Tianwei Song,Caixia Xu
In this work, low-threshold resonant lasing emission was investigated in undoped and Mg-doped GaN thin films on interfacial designed sapphire substrates. The scattering cross-section of the periodic resonant structure was evaluated by using the finite difference time domain (FDTD) method and was found to be beneficial for reducing the threshold and enhancing the resonant lasing emission within the periodic structures. Compared with undoped and Si-doped GaN thin films, p-type Mg-doped GaN thin films demonstrated a better lasing emission performance. The lasing energy level system and defect densities played vital roles in the lasing emission. This work is beneficial to the realization of multifunctional applications in optoelectronic devices.Keywords:gallium nitride;lasing action;resonant structure;patterned sapphire substrate
研究领域:
光学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 6
·899
·
IF 5.719
Xiaoyan Wu,Wei Li,Qingrong Chen,Caixia Xu,Jiamian Wang,Lingyuan Wu,Guodong Liu,Weiping Wang,Ting Li,Ping Chen,Long Xu
Light-induced degradation (LID) phenomenon is commonly found in optoelectronics devices. Self-healing effect in halide lead perovskite solar cells was investigated since the electrons and holes in the shallow traps could escape easily at room temperature. However, the degradation in the semiconductors could not easily recover at room temperature, and many of them needed annealing at temperatures in the several hundreds, which was not friendly to the integrated optoelectronic semiconductor devices. To solve this problem, in this work, LID effect of photocurrent in p-type Mg-doped gallium nitride thin films was investigated, and deep defect and vacancy traps played a vital role in the LID and healing process. This work provides a contactless way to heal the photocurrent behavior to its initial level, which is desirable in integrated devices.Keywords:Mg-doped gallium nitride;light-induced degradation;photocurrent device;contactless healing
研究领域:
材料科学
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光电子学
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半导体物理
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DOI
PubMed
高影响因子
Photonics Research
·
2025
·Vol. 13
·期 6
·1544-1553
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IF 7.2
Can Zou,Qing Liu,Lu Zhang,Xiao Tang,Xiaohang Li,Shuti Li,Shuti Li,Fangliang Gao,Fangliang Gao
This study pioneers a high-performance UV polarization-sensitive photodetector by ingeniously integrating non-centrosymmetric metal nanostructures into a graphene (Gr)/Al2O3/GaN heterojunction. Unlike conventional approaches constrained by graphene’s intrinsic isotropy or complex nanoscale patterning, our design introduces asymmetric metal architectures (E-/T-type) to artificially create directional anisotropy. These structures generate plasmon-enhanced localized electric fields that selectively amplify photogenerated carrier momentum under polarized UV light (325 nm), synergized with Fowler-Nordheim tunneling (FNT) across an atomically thin Al2O3 barrier. The result is a breakthrough in performance: a record anisotropy ratio of 115.5 (E-type, −2 V) and exceptional responsivity (97.7 A/W), surpassing existing graphene-based detectors by over an order of magnitude. Crucially, by systematically modulating metal geometry and density, we demonstrate a universal platform adaptable to diverse 2D/3D systems. This study provides a valuable reference for developing and practically applying photodetectors with higher anisotropy than ultraviolet polarization sensitivity.
研究领域:
光学工程
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纳米材料
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半导体器件
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2025
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IF 21.1
Xuewei Hao,Jiaming Wu,Xintong Cai,Keyan Li,Chunshan Song,Xinwen Guo
The development of photocatalysts for efficient CO 2 conversion to chemicals especially C 2+ products remains a challenge. In this work, Ag nanoparticles (NPs) decorated GaN photocatalysts were synthesized by in-situ nitridation of Ga 2 O 3 combined with chemical deposition of Ag. The photocatalytic performance of Ag/GaN photocatalysts was optimized by tuning the loading amount and ripening time of Ag NPs, among which 0.3Ag/GaN exhibited best photocatalytic CO 2 reduction performance. The production rates of CO and CH 4 reached 421 and 80 μmol g −1 h −1 , respectively, and especially, it also produced C 2 H 6 with a production rate of 79 μmol g −1 h −1 . The introduction of Ag NPs not only significantly promotes visible light absorption as well as charge generation and separation, but also elevates surface temperature of the photocatalyst due to photothermal effect, resulting from localized surface plasmon resonance (LSPR) effect of Ag NPs. Moreover, the addition of Ag NPs enhances the adsorption of both CO 2 and the *CO intermediate, facilitating the CO 2 activation and subsequent C−C coupling process. This study provides new ideas for the design and preparation of photocatalysts capable of converting CO 2 into value-added chemicals.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
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2024
·Vol. 39
·期 4
·814-818
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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
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纳米技术
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产品关联
DOI
高影响因子
APPLIED OPTICS
·
2025
·Vol. 64
·期 10
·2554-2560
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IF 1.7
Xiaodong Zhang,Kang Xiang,Muyang Ye,Shuang Gao,Xiujuan Wang
Ultraviolet photodetectors (UV-PDs) with high sensitivity and fast optical response have become an important part of modern optoelectronic information transmission and communication systems. In this paper, a high-performance self-powered titanium carbide (${{\rm Ti}_{3}}{\rm C_2}{\rm T_x}$)/gallium nitride (GaN) Schottky UV-PD with an interdigitated electrode was developed. A Schottky-contacted ${{\rm Ti}_{3}}{\rm C_2}{\rm T_x}$ interdigitated electrode was successfully fabricated on GaN substrates using a spray coating method. The as-prepared ${{\rm Ti}_{3}}{\rm C_2}{\rm T_x}/{\rm GaN}$ UV-PD exhibits excellent optoelectronic properties. Under zero bias and weak UV illumination (${48}\;\unicode{x00B5} {{\rm W/cm}^{2}}$), the device demonstrates an ultra-low dark current (${2.818} \times {{10}^{- {10}}}\;{\rm A}$) and a fast response speed (${{\rm t}_{\rm r}} = {170}\;\unicode{x00B5} {{\rm s/t}_{\rm f}} = {210}\;\unicode{x00B5} {\rm s}$); the responsivity and detectivity could reach 120.78 mA/W and ${1.272} \times {{10}^{{12}}}$ Jones, respectively. Furthermore, to demonstrate the feasibility of practical application, the device was applied in a UV point-of-view imaging system and high-quality images were successfully obtained under low-light conditions. This work presents an effective approach in developing high-performance UV-PDs for optical imaging applications.
研究领域:
材料科学
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光电技术
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产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Dan Han,Yi Chen,Donghui Li,Jiexu Shi,Hongtao Wang,Xiuli He,Li Zhao,Weidong Wang,Shengbo Sang,Jianlong Ji
Surface modification with noble metal is considered as an effective strategy to enhance sensing performance of semiconductor gas sensors. In this work, gold nanoparticles (Au NPs) decorated Gallium Nitride nanoflowers (Au-GaN NFs) have been synthesized successfully by a feasible hydrothermal method combined with high temperature nitridation and followed by in-situ reduction process. The characterizations of the structure and morphology of as-obtained Au-GaN NFs indicated that the Au NPs were successfully loaded on the surface of GaN. The excellent gas sensing performance was observed for GaN of 2 mol% Au loaded, including the high response (86.8 %) to 100 ppm NH 3 with fast response/recovery time (41 s/169 s) at room temperature , low theoretical limit of detection (72 ppb), good stability and selectivity. Besides, the influence of humidity on the performance of sensors was explored, where the response can be reached 56.5 % towards 100 ppm NH 3 under 70 % RH. The improvement of the sensing performance of Au-GaN NFs sensor can be attributed to the combined action of chemical and electronic sensitization of Au NPs. This work provides a candidate of Au-GaN NFs for the development of wireless sensing system in NH 3 monitoring.
研究领域:
材料科学
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传感器技术
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产品关联
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
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物理学
·
电子工程
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产品关联
DOI
PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
Zhen Xu,Shuyue Yang,Dizi Yang,Dongmei Zhang,Panpan Sun,Shibing Ni
Porous architecture of N-doped carbon coated gallium nitride sub-micrometer bricks comprising of nanoscale carbon-coating primary nanoparticles/reduced graphene oxide hybrids (GaN–NC–RGO) are firstly designed as high-performance anode for lithium-ion batteries (LIBs). The GaN–NC–RGO electrode shows excellent electrochemical performance , with the integral porous architecture and the GaN nanoparticles enhancing the reaction activity, the nanoscale NC coating and the microscale RGO hybridization facilitating electron transfer , and the submicron size of the GaN bricks improving the tap density. The GaN–NC–RGO electrode delivers high discharge capacity of 398.6 mAh g −1 after 550 cycles at 0.05 A g −1 , and this value increases to 445.4 mAh g −1 at 0.02 A g −1 . After 5 periodic rate capability testing over 400 cycles, the discharge capacity of the GaN–NC–RGO electrode can be fully recovered when reverting current to 0.05 A g −1 . The feasible electrode design strategy coupled with the facile fabrication approach and the impressive performances of the GaN–NC–RGO electrode may be referential for the development of high-performance GaN-based materials for LIBs.
研究领域:
材料科学
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电化学
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能源存储
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产品关联
DOI
高影响因子
ECS Journal of Solid State Science and Technology
·
2021
·Vol. 10
·期 12
·124004
·
IF 2.07
Zhao Ding,Shiwei Niu,Qingyu Yao,Yongguang Wang,Huaijun Guan,Dong Zhao,Zexin Yu
Overcoming the low fabricating efficiency of traditional chemical mechanical polishing (CMP) for Gallium nitride (GaN) is a challenge owing to its high hardness, high brittleness, and chemical inertness. Here, electrochemical etching is proposed to increase the material removal rate and acquire a high-quality surface on GaN wafers. To reveal the synergistic etching mechanism of oxidizing agent and corrosion inhibitor on the GaN wafers, electrochemical etching experiments were carried out. The optimal etching solution contained 4 wt% H2O2 and 10 mmol l−1 purified terephthalic acid. Experiments with various polishing parameters were comparatively investigated to verify the auxiliary effect of etching and determine the ideal parameters. Cathodoluminescence spectroscopy shows that the electrochemical etching removes the SSDs completely and the CMP process with befitting parameters does not induce supernumerary SSDs.
研究领域:
材料科学
·
半导体技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）