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International Journal of Minerals,Metallurgy and materials 2025年第1期32卷 147-153页

作者： Junjie Li Wenbo Yu Zhenyu Sun Weichen Zheng Liangwei Zhang Yanling Xue Wenning Liu Shoumei Xiong center of materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Traffic&Transportation Engineering Central South UniversityChangsha 410075China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China School of materials Science and Engineering Tsinghua UniversityBeijing 100084China

High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile *** can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated ***,the development of non-heat treatment Al alloys is becoming the hot *** addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of *** achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and *** influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic *** results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased ***,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical *** introduction of Ce resulted in the poisoning effect and reduced mechanical properties.

关键词： aluminium alloy high-pressure die-casting externally solidified crystals non-heat treatment

Performance improvement in polymeric thin film transistors using chemically modified both silver bottom contacts and dielectric surfaces

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Chinese Physics B 2015年第9期24卷 403-407页

作者：谢应涛欧阳世宏王东平朱大龙许鑫谭特方汉铿 Department of electronic Engineering Center for Opto–Electronic Materials and DevicesShanghai Jiao Tong University National Engineering Laboratory for TFT-LCD Key materials and Technologies

An efficient interface modification is introduced to improve the performance of polymeric thin film transistors. This efficient interface modification is first achieved by 4-fluorothiophenol（4-FTP） self-assembled monolayers（SAM） to chemically treat the silver source–drain（S/D） contacts while the silicon oxide（SiO2） dielectric interface is further primed by either hexamethyldisilazane（HMDS） or octyltrichlorosilane（OTS-C8）. Results show that contact resistance is the dominant factor that limits the field effect mobility of the PTDPPTFT4 transistors. With proper surface modification applied to both the dielectric surface and the bottom contacts, the field effect mobilities of the bottom-gate bottom-contact PTDPPTFT4 transistors were significantly improved from 0.15 cm^2·V^-1·s^-1 to 0.91 cm^2·V^-1·s^-1.

关键词： polymeric thin film transistors orthogonal self-assembly chemically modified gate dielectric chemically modified silver bottom c

Performance improvement of AlGaN-based deep ultraviolet light-emitting diodes with double electron blocking layers

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Chinese Physics B 2016年第2期25卷 538-543页

作者：张诚孙慧卿李旭娜孙浩范宣聪张柱定郭志友 Laboratory of Nanophotonic Functional materials and devices Institute of Opto-Electronic Materials and TechnologySouth China Normal University

The AlGaN-based deep ultraviolet light-emitting diodes（LED） with double electron blocking layers（d-EBLs） on both sides of the active region are investigated theoretically. They possess many excellent performances compared with the conventional structure with only a single electron blocking layer, such as a higher recombination rate, improved light output power and internal quantum efficiency（IQE）. The reasons can be concluded as follows. On the one hand, the weakened electrostatic field within the quantum wells（QWs） enhances the electron–hole spatial overlap in QWs, and therefore increases the probability of radioactive recombination. On the other hand, the added n-AlGaN layer can not only prevent holes from overflowing into the n-side region but also act as another electron source, providing more electrons.

关键词： double electron blocking layers ultraviolet light-emitting diodes n-A1GaN electrostatic field

electronic structures and optical properties of Ⅲ_A-doped wurtzite Mg_(0.25)Zn_(0.75)O

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Chinese Physics B 2014年第8期23卷 430-435页

作者：郑树文何苗李述体章勇 Laboratory of Nanophotonic Functional materials and devices Institute of Opto-electronic Materials and TechnologySouth China Normal University

The energy band structures, density of states, and optical properties of IliA-doped wurtzite Mg0.25Zn0.75O （IIIA= A1, Ga, In） are investigated by a first-principles method based on the density functional theory. The calculated results show that the optical bandgaps of Mg0.25Zn0.75O：IIIA are larger than those of Mg0.25Zn0.75O because of the Burstein-Moss effect and the bandgap renormalization effect. The electron effective mass values of Mg0.25Zn0.75O：IIIA are heavier than those of Mgo.25Zno.750, which is in agreement with the previous experimental result. The formation energies of MgZnO：Al and MgZnO：Ga are smaller than that of MgZnO：In, while their optical bandgaps are larger, so MgZnO：Al and MgZnO：Ga are suitable to be fabricated and used as transparent conductive oxide films in the ultra-violet （UV） and deep UV optoelectronic devices.

关键词： first-principles Mg0.25Zn0.75O electronic structure optical bandgap

electronic structures and energy band properties of Be- and S-doped wurtzite ZnO

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Chinese Physics B 2014年第6期23卷 426-432页

作者：郑树文范广涵何苗张涛 Laboratory of Nanophotonic Functional materials and devices Institute of Opto-electronic Materials and TechnologySouth China Normal University

The energy band properties, density of states, and band alignment of the BexZn1-xO1-ySy alloy （Be- and S-doped wurtzite ZnO） are investigated by the first-principles method. BexZn1-xO1-ySy alloy is a direct band gap semiconductor, the valence band maximum （VBM） and the conduction band minimum （CBM） of BexZn1-xO1-ySy are dominated by S 3p and Zn 4s states, respectively. The band gap and lattice constant of BexZn1-xO1-ySy alloy can be modulated by changing the doped content values x and y. With the increase in Be content value x in the BexZnl-xOl-ySy alloy, the band gap increases and the lattice constant reduces, but the situation is just the opposite when increasing the S content value y in the BexZn1-xO1-ySy alloy. Because the lattice constant of Be0.375Zn0.625O0.75S0.25 alloy is well matched with that of ZnO and its energy gap is large compared with that of ZnO, so the Be0.375Zn0.625O0.75S0.25 alloy is suitable for serving as the blocking material for a high-quality ZnO-based device.

关键词： first-principle BexZn1-xO1-ySy alloy electronic structure band gap modulation

Micro-light-emitting-diode array with dual functions of visible light communication and illumination

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Chinese Physics B 2017年第10期26卷 490-495页

作者：黄涌郭志友孙慧卿黄鸿勇 Guangdong Provincial Key Laboratory of Nanophotonic Functional materials and devices Institute of the opto-electronic materials and Technology South China Normal University Guangdong Engineering Technology Research center of optoelectronic Functional materials and devices

We demonstrate high-speed blue 4 ×4 micro-light-emitting-diode （LED） arrays with 14 light-emitting units （two light-emitting units are used as the positive and negative electrodes for power supply, respectively） comprising multiple quantum wells formed of GaN epitaxial layers grown on a sapphire substrate, and experimentally test their applicability for being used as VLC transmitters and illuminations. The micro-LED arrays provide a maximum -3-dB frequency response of 60.5 MHz with a smooth frequency curve from 1 MHz to 500 MHz for an optical output power of 165 mW at an injection current of 30 mA, which, to our knowledge, is the highest response frequency ever reported for blue GaN-based LEDs operating at that level of optical output power. The relationship between the frequency and size of the device single pixel diameter reveals the relationship between the response frequency and diffusion capacitance of the device.

关键词： light-emitting devices optical communications diffusion capacitance

Advantages of InGaN/GaN multiple quantum well solar cells with stepped-thickness quantum wells

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Chinese Physics B 2013年第7期22卷 574-577页

作者：陈鑫赵璧君任志伟童金辉王幸福卓祥景章俊李丹伟易翰翔李述体 Laboratory of Nanophotonic Functional materials and devices Institute of Opto-electronic Materials and TechnologySouth China Normal University

InGaN/GaN multiple quantum well （MQW） solar cells with stepped-thickness quantum wells （SQW） are designed and grown by metal-organic chemical vapor deposition. The stepped-thickness quantum wells structure, in which the well thickness becomes smaller and smaller along the growth direction, reveals better crystalline quality and better spectral overlap with the solar spectrum. Consequently, the short-circuit current density （Jsc） and conversion efficiency of the solar cell are enhanced by 27.12% and 56.41% compared with the conventional structure under illumination of AM1.5G （100 mW/cm2）. In addition, approaches to further promote the performance of InGaN/GaN multiple quantum well solar cells are discussed and presented.

关键词： metal organic chemical vapor deposition (MOCVD) GaN based solar cells stepped-thickness quantum wells

Efficiency and droop improvement in a blue InGaN-based light emitting diode with a p-InGaN layer inserted in the GaN barriers

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Chinese Physics B 2013年第9期22卷 644-647页

作者：王幸福童金辉赵璧君陈鑫任志伟李丹伟卓祥景章俊易翰翔李述体 Laboratory of Nanophotonic Functional materials and devices Institute of Opto-Electronic Materials and TechnologySouth China Normal University

The advantages of a blue InGaN-based light-emitting diode with a p-InGaN layer inserted in the GaN barriers is studied. The carrier concentration in the quantum well, radiative recombination rate in the active region, output power, and internal quantum efficiency are investigated. The simulation results show that the InGaN-based light-emitting diode with a p-InGaN layer inserted in the barriers has better performance over its conventional counterpart and the light emitting diode with p-GaN inserted in the barriers. The improvement is due to enhanced Mg acceptor activation and enhanced hole injection into the quantum wells.

关键词： GaN-based light-emitting diodes p-InGaN layers Mg acceptor

Enhanced performance of GaN-based light-emitting diodes with InGaN/GaN superlattice barriers

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Chinese Physics B 2014年第5期23卷 630-633页

作者：蔡金鑫孙慧卿郑欢张盼君郭志友 Laboratory of Nanophotonic Functional materials and devices Institute of Opto-Electronic Materials and TechnologySouth China Normal University

GaN-based multiple quantum well light-emitting diodes （LEDs） with conventional and superlattice barriers have been investigated numerically. Simulation results demonstrate using InGaN/GaN superlattices as barriers can effectively enhance performances of the GaN-Based LEDs, mainly owing to the improvement of hole injection and transport among the MQW active region. Meanwhile, the improved electron capture decreases the electron leakage and alleviates the efficiency droop. The weak polarization field induced by the superlattice structure strengthens the intensity of the emission spectrum and leads to a blue-shift relative to the conventional one.

关键词： superlattice barrier numerical simulation hole injection GaN-based LED

Enhanced performance of InGaN/GaN multiple quantum well solar cells with double indium content

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Chinese Physics B 2013年第8期22卷 698-701页

作者：赵璧君陈鑫任志伟童金辉王幸福李丹伟卓祥景章俊易翰翔李述体 Laboratory of Nanophotonic Functional materials and devices Institute of Opto-Electronic Materials and Technology South China Normal University

The performance of a multiple quantum well （MQW） InGaN solar cell with double indium content is investigated. It is found that the adoption of a double indium structure can effectively broaden the spectral response of the external quantum efficiencies and optimize the overall performance of the solar cell. Under AM1.5G illumination, the short-circuit current density （Jsc） and conversion efficiency of the solar cell are enhanced by 65% and 13% compared with those of a normal single-indium-content MQW solar cell. These improvements are mainly attributed to the expansion of the absorption spectrum and better extraction efficiency of the photon-generated carriers induced by higher polarization.

关键词： metal-organic chemical vapor deposition GaN-based solar cells InGaN/GaN multiple quantumwells