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Chinese Physics Letters 2017年第1期34卷 137-140页

作者：汤寅蔡青杨莲红董可秀陈敦军陆海张荣郑有炓 Key laboratory of Advanced photonic and electronic materials School of electronic Science and EngineeringNanjing University department of Physics Changji College School of Mechanical and electronic engineering Chuzhou University

It is well known that -nitride semiconductors can generate the magnitude of MV/cm polarization electric field which is comparable with their ionization electric fields. To take full advantage of the polarization electric field, we design an N-face AlGaN solar-blind avalanche photodiode (APD) with an Al0.45Ga0.55N/Al0.3Ga0.7N heterostructure as separate absorption and multiplication (SAM) regions. The simulation results show that the N-face APDs are more beneficial to improving the avalanche gain and reducing the avalanche breakdown voltage compared with the Ga-face APDs due to the effect of the polarization electric field. Furthermore, the Al0.45Ga0.55N/Al0.3Ga0.7N heterostructure SAM regions used in APDs instead of homogeneous Al0.45Ga0.55N SAM structure can increase significantly avalanche gain because of the increased hole ionization coefficient by using the relatively low Al-content AlGaN in the multiplication region. Meanwhile, a quarter-wave AlGaN/AlN distributed Bragg reflector structure at the bottom of the device is designed to remain a solar-blind characteristic of the heterostructure SAM-APDs.

关键词： AlGaN APD High-Gain N-Face AlGaN Solar-Blind Avalanche Photodiodes Using a Heterostructure as Separate Absorption and Multiplication Regions

Potassium sodium tartrate-assisted hydrothermal synthesis of BaLuFs ：Yb3＋/Er3＋ nanocrystals

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Particuology 2016年第1期14卷 164-169页

作者： Rongjin Sun Peiyu Qiu Ting Yin Guo Gao Hualin Fu Kan Wang Chunlei Zhang Daxiang Cui Institute of Nano Biomedicine and engineering Department of Instrument Science and Technology Key Laboratory for Thin Film and MicrofabricationTechnology of Ministry of Education School of Electronic Information and Electrical Engineering School of Materials Science and Engineering Shanghai JiaoTong University Shanghai 200240 China

Highly-dispersed BaLuFs：yb3＋/Er3＋ nanocrystals were prepared by a facile potassium sodium tartrate- assisted hydrothermal method. The average particle size was approximately 20-25 nm. The formation mechanism is discussed. Potassium sodium tartrate led to form a complex with an approximately three- dimensional network structure, which insured largely concurrent nucleation. As a result, we acquired uniform nanoparticles. The hydrothermal temperature, holding time, and pH value were important fac- tors affecting the formation of the BaLuF5 ：yb3＋/Er3＋ nanocrystals. We investigated their influence on the formation and realized the optimal reaction parameters. Remarkably, potassium sodium tartrate also con- tributed to the biocompatibility and potential biomedical applications of BaLuFs ：Yb3＋/Er3＋ nanocrystals by decomposing into small organic groups attached to the nanoparticles.

关键词： Upconversion BaLuFs PST Hydrothermal synthesis

Functional plastic films:nano-engineered composite based flexible microwave antennas with near-unity relative visible transmittance

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Light(Advanced Manufacturing) 2024年第2期5卷 95-105页

作者： Cheng Zhang Liang Zhu Chengang Ji Zhilu Ye Nabeel Alsaab Minye Yang Yuhui Hu Pai-Yen Chen L.Jay Guo School of Optical and electronic Information&Wuhan National laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074China department of Electrical and Computer engineering University of Illinois at ChicagoChicagoIL 60607USA department of Electrical engineering and Computer science University of MichiganAnn ArborMI 48109USA

Microwave antennas are essential elements for various applications,such as telecommunication,radar,sensing,and wireless power *** antennas are conventionally manufactured on rigid substrates using opaque materials,such as metal strips,metallic tapes,or epoxy pastes;thus,prohibiting their use in flexible and wearable devices,and simultaneously limiting their integration into existing optoelectronic ***,we demonstrate that mechanically flexible and optically transparent microwave antennas with high operational efficiencies can be readily fabricated using composite nanolayers deposited on common plastic *** composite nanolayer structure consists of an ultra-thin copper-doped silver film sandwiched between two dielectric films of tantalum pentoxide and aluminum *** material and thickness of each constituent layer are judiciously selected such that the whole structure exhibits an experimentally measured averaged visible transmittance as high as 98.94%compared to a bare plastic substrate,and simultaneously,a sheet resistance as low as 12.5Ω/*** representative types of microwave antennas are implemented:an omnidirectional dipole antenna,unidirectional Yagi-Uda antenna,low-profile patch antenna,and Fabry-Pérot cavity *** devices exhibit great mechanical flexibility with bending angle over 70°,high gain of up to 13.6 dBi,and large radiation efficiency of up to 84.5%.The proposed nano-engineered composites can be easily prepared over large areas on various types of substrates and simultaneously overcome the limitations of poor mechanical flexibility,low electrical conductivity,and reduced optical transparency usually faced by other constituent materials for flexible transparent microwave *** demonstrated flexible microwave antennas have various applications ranging from fifth-generation and vehicular communication systems to bio-signal monitors and wearable electronics.

关键词： Optically transparent antenna Flexible microwave antenna Transparent conductor Ultra-thin silver Doped silver Wearable optoelectronics

High Deep-Ultraviolet Quantum Efficiency GaN P–I–N Photodetectors with thin P-GaN Contact Layer

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Chinese Physics Letters 2013年第1期30卷 169-171页

作者： LIAN Hai-Feng WANG Guo-Sheng LU Hai REN Fang-Fang CHEN Dun-Jun ZHANG Rong ZHENG You-Dou Jiangsu Provincial Key laboratory of Advanced photonic and electronic materials and School of Electronic Science and EngineeringNanjing UniversityNanjing 210093

GaN ultraviolet(UV)p-i-n photodetectors(PDs)with a 40 nm thin p-GaN contact layer are fabricated on sapphire substrates,which exhibit enhanced quantum efficiency especially in a deep-UV wavelength *** PDs show good rectification behavior and low dark current in pA level for reverse bias up to-10 *** zero bias,the maximum quantum efficiency of the PD at 360 nm is close to 59.4%with a UV/visible rejection ratio more than 4 orders of *** at a short wavelength of 280 nm,the quantum efficiency of the PD is still around 47.5%,which is considerably higher than that of a control device with a thicker p-GaN contact *** room temperature thermal noise limited detectivity of the PD is calculated to be~4.96×10^(14) cm·Hz^(1/2)W^(-1).

关键词： Efficiency sapphire quantum

Enhanced thermoelectric performance in Ga_(x)Co_(4)Sb_(12.3-y)Te_(y) skutterudites via suppressing bipolar effects for commercial application

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Journal of Materiomics 2020年第2期6卷 240-247页

作者： Jing Jiang Rui Zhang Chengcheng Yang Yi Niu Ting Zhou Yan Pan Chao Wang Clean Energy materials and engineering Center State Key Laboratory of Electronic Thin Film and Integrated DeviceSchool of Electronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengdu611731China

The n-type filled and doped skutterudites Ga_(x)Co_(4)Sb_(12.3) and Ga_(0.2)Co_(4)Sb_(11.3)Te composites with the welldistributed GaSb nanoinclusions are synthesized through the manipulating of metastable Ga fillers and enrichment of Sb by an in-situ method with a proper annealing *** atoms can fill the icosahedron cages of skutterudite at high temperature,but at low temperature,they are driven out from the lattice voids and form the second phase of GaSb at grain *** presence of GaSb second phases reduces the thermal conductivity *** doping leads to a significant increase in carrier concentration of Ga_(0.2)Co_(4)Sb_(11.3)Te,thus largely suppresses the bipolar effect of Ga_(x)Co_(4)Sb_(12.3),resulting in a great enhancement in power ***,Te doping induces mass and strain fluctuation,which decreases the lattice thermal conductivity ***,the maximum ZT is increased from 0.56 for Ga_(0.2)Co_(4)Sb_(12.3) at 573 K to 1.48 for Ga_(0.2)Co_(4)Sb_(11.3)Te at 873 K,which is advantageous to improve the thermoelectric conversion efficiency for commercial application.

关键词： Thermoelectric Skutterudite Second phase Bipolar effect

Resonant tunnelling in nc-Si/SiO_2 multilayers at room temperature

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Journal of Semiconductors 2011年第8期32卷 23-26页

作者：陈德媛 College of electronic science & engineering Nanjing University of Posts and Telecommunications Nanjing National laboratory of Microstructures and Key laboratory of Advanced photonic and electronic materials Department of PhysicsNanjing University

Nc-Si/SiO_2 multilayers were fabricated on silicon wafers in a plasma enhanced chemical vapour deposition system using in situ oxidation technology,followed by three-step thermal *** transportation at room temperature is characterized by current voltage measurement,and negative different conductances can be observed both under forward and negative biases,which is explained by resonant *** resonant tunnelling peak voltage is related to the thicknesses of the nc-Si and SiO_2 *** the resonant tunnelling peak voltage under negative bias is larger than that under forward *** energy band diagram and an equivalent circuit diagram were constructed to analyze and explain the above transportation process and properties.

关键词： resonant tunnelling work function quantum dots

Quantum-mechanical effects in photoluminescence from thin crystalline gold films

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Light(science & Applications) 2024年第4期13卷 783-794页

作者： Alan R.Bowman Alvaro Rodríguez Echarri Fatemeh Kiani Fadil Iyikanat Ted V.Tsoulos Joel D.Cox Ravishankar Sundararaman F.Javier García de Abajo Giulia Tagliabue laboratory of Nanoscience for Energy Technologies(LNET) STIÉcole Polytechnique Fédérale de Lausanne(EPFL)LausanneSwitzerland ICFO–Institut de Ciencies Fotoniques The Barcelona Institute of Science and TechnologyCastelldefels(Barcelona)Spain. MBI–Max-Born-Institut BerlinGermany. POLIMA–Center for Polariton-driven Light–Matter Interactions University of Southern DenmarkOdense MDenmark. Danish Institute for Advanced Study University of Southern DenmarkOdense MDenmark. department of materials science&engineering Rensselaer Polytechnic InstituteTroyNYUSA. department of Physics Applied Physicsand AstronomyRensselaer Polytechnic InstituteTroyNYUSA. ICREA–Institucio Catalana de Recerca i Estudis Avancats BarcelonaSpain

Luminescence constitutes a unique source of insight into hot carrier processes in metals,including those in plasmonic nanostructures used for sensing and energy ***,being weak in nature,metal luminescence remains poorly understood,its microscopic origin strongly debated,and its potential for unraveling nanoscale carrier dynamics largely ***,we reveal quantum-mechanical effects in the luminescence emanating from thin monocrystalline gold ***,we present experimental evidence,supported by first-principles simulations,to demonstrate its photoluminescence origin(i.e.,radiative emission from electron/hole recombination)when exciting in the interband *** model allows us to identify changes to the measured gold luminescence due to quantum-mechanical effects as the gold film thickness is ***,such effects are observable in the luminescence signal from flakes up to 40 nm in thickness,associated with the out-of-plane discreteness of the electronic band structure near the Fermi *** qualitatively reproduce the observations with first-principles modeling,thus establishing a unified description of luminescence in gold monocrystalline flakes and enabling its widespread application as a probe of carrier dynamics and light-matter interactions in this *** study paves the way for future explorations of hot carriers and charge-transfer dynamics in a multitude of material systems.

关键词： luminescence quantum crystalline

Soliton microcomb generation by cavity polygon modes

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Opto-electronic Advances 2024年第8期7卷 6-14页

作者： Botao Fu Renhong Gao Ni Yao Haisu Zhang Chuntao Li Jintian Lin Min Wang Lingling Qiao Ya Cheng State Key laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser science Shanghai Institute of Optics and Fine Mechanics(SIOM)Chinese Academy of Sciences(CAS)Shanghai 201800China Research Center for Frontier Fundamental Studies Zhejiang LabHangzhou 311100China engineering Research Center for Nanophotonics&Advanced Instrument Ministry of EducationSchool of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China School of Physical science and Technology ShanghaiTech UniversityShanghai 200031China Center of materials science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China Shanghai Research Center for Quantum sciences Shanghai 201315China Hefei National laboratory Hefei 230088China

Soliton microcombs,which require the hosting cavity to operate in an anomalous dispersion regime,are essential to integrate photonic *** the past,soliton microcombs were generated on cavity whispering gallery modes(WGMs),and the anomalous dispersion requirement of the cavity made by normal dispersion material was achieved through structural dispersion *** inevitably degrades the cavity optical quality factor(Q)and increases pump threshold power for soliton comb *** overcome the challenges,here,we report a soliton microcomb excited by cavity polygon *** modes display anomalous dispersion at near-infrared while optical Q factors exceeding 4×10^(6) are ***,a soliton comb spanning from 1450 nm to 1620 nm with a record low pump power of 11 m W is demonstrated,a three-fold improvement compared to the state of the art on the same material platform.

关键词： thin-film lithium niobate nonlinear optics microresonators

Room-temperature ferromagnetism induced by Cu vacancies in Cu_x(Cu_2O)_(1-x) granular films

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Chinese Physics B 2015年第9期24卷 518-522页

作者：解新建李好博王卫超卢峰于红云王维华程雅慧郑荣坤刘晖 School of materials science and engineering Hebei University of Technology department of electronics and Tianjin Key laboratory of Photo-electronic thin film Device and Technology Nankai University Center for Testing and Analyzing of materials School of Materials Science and EngineeringTsinghua University School of Physics University of Sydney

Cux（Cu2O）1-x（0.09 x 1.00） granular films with thickness about 280 nm have been fabricated by direct current reactive magnetron sputtering. The atomic ratio x can be controlled by the oxygen flow rate during Cux（Cu2O）1-x deposition. Room-temperature ferromagnetism（FM） is found in all of the samples. The saturated magnetization increases at first and then decreases with the decrease of x. The photoluminescence spectra show that the magnetization is closely correlated with the Cu vacancies in the Cux（Cu2O）1-x granular films. Fundamentally, the FM could be understood by the Stoner model based on the charge transfer mechanism. These results may provide solid evidence and physical insights on the origin of FM in the Cu2O-based oxides diluted magnetic semiconductors, especially for systems without intentional magnetic atom doping.

关键词： Cux(Cu2O)1-x granular films room-temperature ferromagnetism oxide diluted magnetic semiconductors

Photoluminescent properties of Sb^(3+)-doped and(Sb^(3+),Eu^(3+))co-doped YBO3 phosphors prepared via hydrothermal method and solid-state process

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Frontiers of Chemical science and engineering 2011年第4期5卷 429-434页

作者： Fushan WEN Lingling SUN Jinhyeok KIM College of Chemistry&Chemical engineering China University of PetroleumDongying 257061China photonic and electronic thin film laboratory Department of Materials Science and EngineeringChonnam National UniversityKwangju 500–757Republic of Korea

Sb^(3+)-doped YBO3 crystals were prepared through a low-temperature hydrothermal method and a high-temperature solid-state technique,*** effects of preparation methods on the morphologies and luminescent properties of YBO_(3) phosphors were *** YBO3 crystals from the hydrothermal system look likeﬂowers,whereas those from the solid-state process look like some agglomerates of little *** Sb^(3+)-doped YBO3 powders prepared via both methods showed the blue emission with the peak at around 452 nm,which corresponds to the 3P1→1S0 transition of Sb^(3+)***,the emission intensity of the Sb^(3+)-doped YBO3 from the hydrothermal system is about 3.5 times as much as that from the solid-state ***(Sb^(3+),Eu^(3+))co-doped YBO3 crystals were also prepared through the two *** results showed that the emission intensity of Sb^(3+)ions in(Sb^(3+),Eu^(3+))co-doped YBO3 synthesized by the hydrothermal method is stronger than that by the solid-state process.

关键词： hydrothermal solid-state luminescent borate