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    Not found SPECIAL TOPIC — A celebration of the 100th birthday of Kun Huang

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    Charge trapping memory device based on the Ga2O3 films as trapping and blocking layer
    Bing Bai(白冰), Hong Wang(王宏), Yan Li(李岩), Yunxia Hao(郝云霞), Bo Zhang(张博), Boping Wang(王博平), Zihang Wang(王子航), Hongqi Yang(杨红旗), Qihang Gao(高启航), Chao Lü(吕超), Qingshun Zhang(张庆顺), Xiaobing Yan(闫小兵)
    Chin. Phys. B, 2019, 28 (10): 106802.   DOI: 10.1088/1674-1056/ab3e62
    Abstract266)   HTML    PDF (3326KB)(216)      
    We present a new charge trapping memory (CTM) device with the Au/Ga2O3/SiO2/Si structure, which is fabricated by using the magnetron sputtering, high-temperature annealing, and vacuum evaporation techniques. Transmission electron microscopy diagrams show that the thickness of the SiO2 tunneling layer can be controlled by the annealing temperature. When the devices are annealed at 760 ℃, the measured C-V hysteresis curves exhibit a maximum 6 V memory window under a ±13 V sweeping voltage. In addition, a slight degradation of the device voltage and capacitance indicates the robust retention properties of flat-band voltage and high/low state capacitance. These distinctive advantages are attributed to oxygen vacancies and inter-diffusion layers, which play a critical role in the charge trapping process.
    Magnetoresistance hysteresis in topological Kondo insulator SmB6 nanowire
    Ling-Jian Kong(孔令剑), Yong Zhou(周勇), Hua-Ding Song(宋化鼎), Da-Peng Yu(俞大鹏), Zhi-Min Liao(廖志敏)
    Chin. Phys. B, 2019, 28 (10): 107501.   DOI: 10.1088/1674-1056/ab3a89
    Abstract341)   HTML    PDF (1379KB)(158)      
    SmB6, a topological Kondo insulator, with a gapped bulk state and metallic surface state has aroused great research interest. Here, we report an exotic hysteresis behavior of magnetoresistance in individual SmB6 nanowire in a temperature range in which both surface and bulk states contribute to the total conductance. Under a magnetic field parallel to the SmB6 nanowire, the resistance suddenly increases at the turning point from up-sweep to down-sweep of the magnetic field. The magnetoresistance hysteresis loops are well consistent with the magnetocaloric effect. Our results suggest that the SmB6 nanowires possess potential applications in the magnetic cooling technology.
    Two-dimensional XSe2 (X=Mn, V) based magnetic tunneling junctions with high Curie temperature
    Longfei Pan(潘龙飞), Hongyu Wen(文宏玉), Le Huang(黄乐), Long Chen(陈龙), Hui-Xiong Deng(邓惠雄), Jian-Bai Xia(夏建白), Zhongming Wei(魏钟鸣)
    Chin. Phys. B, 2019, 28 (10): 107504.   DOI: 10.1088/1674-1056/ab3e45
    Abstract426)   HTML    PDF (3283KB)(450)      
    Two-dimensional (2D) magnetic crystals have attracted great attention due to their emerging new physical phenomena. They provide ideal platforms to study the fundamental physics of magnetism in low dimensions. In this research, magnetic tunneling junctions (MTJs) based on XSe2 (X=Mn, V) with room-temperature ferromagnetism were studied using first-principles calculations. A large tunneling magnetoresistance (TMR) of 725.07% was obtained in the MTJs based on monolayer MnSe2. Several schemes were proposed to improve the TMR of these devices. Moreover, the results of our non-equilibrium transport calculations showed that the large TMR was maintained in these devices under a finite bias. The transmission spectrum was analyzed according to the orbital components and the electronic structure of the monolayer XSe2 (X=Mn, V). The results in this paper demonstrated that the MTJs based on a 2D ferromagnet with room-temperature ferromagnetism exhibited reliable performance. Therefore, such devices show the possibility for potential applications in spintronics.
    Optoelectronic properties analysis of silicon light-emitting diode monolithically integrated in standard CMOS IC
    Yanxu Chen(陈彦旭), Dongliang Xu(许栋梁), Kaikai Xu(徐开凯), Ning Zhang(张宁), Siyang Liu(刘斯扬), Jianming Zhao(赵建明), Qian Luo(罗谦), Lukas W. Snyman, Jacobus W. Swart
    Chin. Phys. B, 2019, 28 (10): 107801.   DOI: 10.1088/1674-1056/ab3e44
    Abstract546)   HTML    PDF (1215KB)(191)      
    Si p+n junction diodes operating in the mode of avalanche breakdown are capable of emitting light in the visible range of 400-900 nm. In this study, to realize the switching speed in the GHz range, we present a transient model to shorten the carrier lifetime in the high electric field region by accumulating carriers in both p and n type regions. We also verify the optoelectronic characteristics by disclosing the related physical mechanisms behind the light emission phenomena. The emission of visible light by a monolithically integrated Si diode under the reverse bias is also discussed. The light is emitted as spatial sources by the defects located at the p-n junction of the reverse-biased diode. The influence of the defects on the electrical behavior is manifested as a current-dependent electroluminescence.