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Thickness-dependent enhanced optoelectronic performance of surface charge transfer-doped ReS2 photodetectors

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Nano Research 2022年第4期15卷 3638-3646页

作者： Peiyu Zeng Wenhui Wang Jie Jiang Zheng Liu Dongshuang Han Shuojie Hu Jiaoyan He Peng Zheng Hui Zheng Liang Zheng Xiaojing Yao Weitao Su dexuan huo Zhangting Wu Zhenhua Ni Yang Zhang Lab for Nanoelectronics and NanoDevices Department of Electronics Science and TechnologyHangzhou Dianzi UniversityHangzhou 310018China School of Physics Southeast UniversityNanjing 211189China Jiangsu Province Special Equipment Safety Supervision and Inspection Institute Wuxi 214170China School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China College of Physics and Hebei Advanced Thin Film Laboratory Hebei Normal UniversityShijiazhuang 050024China Institute of Materials Physics Hangzhou Dianzi UniversityHangzhou 310018China

Surface charge transfer doping has been widely utilized to tune the electronic and optical properties of semiconductor photodetectors based on low-dimensional *** many studies have been conducted on the performance(response time,responsivity,etc.)of doped photodetectors and their mechanisms,they merely examined a specific thickness and did not systematically explore the dependence of doping effects on the number of *** work performs a series of investigations on ReS_(2)photodetectors with different numbers of layers and demonstrates that the p-dopant tetrafluorotetracyanoquinodimethane(F_(4)-TCNQ)converts the deep trap states into recombination centers for few-layer ReS_(2)and induces a vertical p-n junction for thicker ReS_(2).A response time of 200 ms is observed in the decorated 2-layer ReS_(2)photodetector,more than two orders of magnitude faster than the response of the pristine photodetector,due to the disappearance of deep trap states.A current rectification ratio of 30 in the F_(4)-TCNQ-decorated sandwiched ReS_(2)device demonstrates the formation of a vertical p-n junction in a thicker ReS_(2)*** responsivity is as high as 2,000 A/W owing to the strong carrier separation of the p-n *** thicknesses of ReS_(2)enable switching of the prominent operating mechanism between transforming deep trap states into recombination centers and forming a vertical p-n *** thicknessdependent doping effect of a two-dimensional material serves as a new mechanism and provides a scheme toward improving the performance of other semiconductor devices,especially optical and electronic devices based on low-dimensional materials.

关键词： Surface charge transfer doping ReS_(2) thickness response time responsivity tetrafluorotetracyanoquinodimethane(F_(4)-TCNQ)

Effect of B-Site Ordering on the Magnetic Order in Multifunctional La2NiMnO6 Double Perovskite

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Chinese Physics Letters 2020年第10期37卷 48-53页

作者： Dexin Yang Rui Jiang Yaohua Zhang Hui Zhang Senlin Lei Tao Yang Xiaoshi Hu Shuai Huang Jingyuan Ge Kunpeng Su Haiou Wang dexuan huo College of Materials&Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018China College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035China

To obtain various Ni/Mn orderings,we use a low-temperature synthesized method to modulate the Ni/Mn ordering of the ferromagnetic-ferroelastic La2NiMnO6 compound,and the Ni/Mn ordering is estimated by the low-temperature saturation *** microstructures,crystal structures and magnetic properties are investigated,and the Landau theory are used to describe the form and magnitude of the coupling effects between Ni/Mn ordering and magnetic order *** is predicted that the Ni/Mn ordering would be a strong coupling effect with the Curie transition temperatures if the La2NiMnO6 sample stoichiometry is close.

关键词： La2Ni coupling ferromagnetic

Recent progress in exploring the magnetic and magnetocaloric properties of rare earth based double perovskite oxides RE2TT'O6

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Recent progress in exploring the magnetic and magnetocaloric...

中国稀土学会2020学术年会暨江西(赣州)稀土资源绿色开发与高效利用大会

作者： Lingwei Li Yao Cheng Peng Xu Youshun Jia Zhenqian Zhang Yong Li Liang Hu Chenxi Lu dexuan huo Mi Yan Hangzhou Dianzi University Northeastern University Zhejiang University

Nowadays, the magnetic materials with special functional characteristics are played very important roles in the development of our present modern society. The magnetic cooling(MC) technology which is based on the magnetocaloric effect(MCE) of magnetic solids has been considered as an energy-efficient alternative method to our present well used gas compression/expression refrigeration technology. The commercial products of magnetic refrigerators are still in the developing stage, searching and designing magnetic solids with outstanding magnetocaloric performances is one of the most important tasks at present. Moreover, the magnetocaloric performances have also been investigated with respective to a deep understand of the corresponding magnetic phase transitions of the magnetic solids. The rare earth(RE) based double perovskite oxides RE2 TT’O6 have been thoroughly investigated in the field of solid chemistry and physics as well as material science and engineering owing to their promising and beneficial technological applications. Based on the differences in the ionic radii and electronic configurations of T’ and T ions, it is possible to design and realize a variety of fascinating characteristics like electrical conductivity, optical activity and magnetic feature, by a proper selective and combination of the constituent ions. In this talk, our recent progress in the investigation of the structural, magnetic and magnetocaloric properties in several series of RE-based double perovskite oxides RE2 TT’O6 compounds will be presented. Some of them are found to exhibit promising magnetocaloric performances at low temperatures which make them be considerable for cryogenic MC application.

关键词： magnetocaloric effect rare earth based oxides double perovskite magnetic cooling

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一种高稳定性的无片外电容的LDO的设计

电子技术应用 2020年第1期46卷 44-47页

作者：霍德萱张国俊电子科技大学薄膜与器件国家重点实验室

考虑到LDO应用在无分立器件的情况下,针对在无片外电容和无片外电阻的情况下对LDO进行研究设计,在无外接电容的情况下,LDO同样能够输出稳定电压,以应用在DC-DC转换器中为内部电路模块进行供电。并通过调整LDO内部运算放大器结构以及对... 详细信息

考虑到LDO应用在无分立器件的情况下,针对在无片外电容和无片外电阻的情况下对LDO进行研究设计,在无外接电容的情况下,LDO同样能够输出稳定电压,以应用在DC-DC转换器中为内部电路模块进行供电。并通过调整LDO内部运算放大器结构以及对运算放大器进行米勒补偿来调整其零极点,同时在运算放大器内部进行电源隔离的处理,可以显著提高其电源抑制比。最后利用华虹0.18μm的BCD工艺进行仿真。仿真结果表明,此结构具有高稳定性,可以输出稳定电压。

关键词：无片外电容 LDO DC-DC转换器运算放大器米勒补偿

Bi_(2)Fe_(3)AlO_(9)陶瓷的磁介电效应研究

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杭州电子科技大学学报（自然科学版） 2022年第3期42卷 72-76,102页

作者：万凯奇金昊黄帅霍德璇杭州电子科技大学材料与环境工程学院浙江杭州310018

采用溶胶凝胶法合成了具有莫来石结构的单相Bi_(2)Fe_(3)AlO_(9)多铁性陶瓷材料,并对其结构、磁性和磁介电效应展开实验研究。与母相Bi_(2)Fe_(4)AlO_(9)相比,由于Bi_(2)Fe_(3)AlO_(9)中的非磁性离子掺杂破坏了原有的自旋失措结构,因此... 详细信息

采用溶胶凝胶法合成了具有莫来石结构的单相Bi_(2)Fe_(3)AlO_(9)多铁性陶瓷材料,并对其结构、磁性和磁介电效应展开实验研究。与母相Bi_(2)Fe_(4)AlO_(9)相比,由于Bi_(2)Fe_(3)AlO_(9)中的非磁性离子掺杂破坏了原有的自旋失措结构,因此,在温度为70 K附近,样品出现1个亚铁磁转变;当温度进一步降低到24 K时,样品表现出类自旋玻璃相。温度为247 K时,样品的介温曲线出现1个介电峰,其特征温度与频率无明显依赖关系;随着外加磁场的增大,介电特征峰强度增大,特征温度向高温移动,表现出磁介电效应。在特征温度附近表现出正磁介电效应,而在其它温度区间则表现出负磁介电效应。

关键词：磁性多铁性磁介电陶瓷

层状化合物Bi_4Te_3的第一性原理研究

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杭州电子科技大学学报（自然科学版） 2016年第4期36卷 66-70页

作者：李金伟瞿晓丹霍德璇杭州电子科技大学材料物理研究所浙江杭州310018

热电器件为热能与电能的双向转换提供了一种简单、安静、环境友好的方式,在小规模发电和制冷上有广泛应用.为了获得高的能量转换效率,需要高性能的热电材料.采用基于密度泛函理论的第一性原理计算了层状化合物Bi4Te3电子结构和输运特性... 详细信息

热电器件为热能与电能的双向转换提供了一种简单、安静、环境友好的方式,在小规模发电和制冷上有广泛应用.为了获得高的能量转换效率,需要高性能的热电材料.采用基于密度泛函理论的第一性原理计算了层状化合物Bi4Te3电子结构和输运特性,研究其热电性能.利用PBE和m-BJ两种交换关联势计算得到的禁带宽度分别为39meV和81meV,表明其为窄禁带直接半导体.热电输运特性计算结果与实验结果定性一致.通过适当掺杂,有望获得好的热电性能.

关键词： Bi4Te3 热电材料 m-BJ交换关联势第一性原理

钨基Heusler合金W_(2)YZ的电子结构与磁性

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杭州电子科技大学学报（自然科学版） 2021年第5期41卷 67-74页

作者：费丽均程垚赵路加霍德璇杭州电子科技大学材料与环境工程学院浙江杭州310018

采用第一性原理计算方法研究了钨基Heusler合金W_(2)YZ(Y=Mn,Fe,Co;Z=Si,Ge,Sn,Sb,Te)的电子结构和磁学性质,并对不同晶体结构L2_(1)型和XA型下的15种W_(2)YZ合金进行晶体结构优化,结果表明,W_(2)YZ系列合金均具有有序的Hg_(2)CuTi型立... 详细信息

采用第一性原理计算方法研究了钨基Heusler合金W_(2)YZ(Y=Mn,Fe,Co;Z=Si,Ge,Sn,Sb,Te)的电子结构和磁学性质,并对不同晶体结构L2_(1)型和XA型下的15种W_(2)YZ合金进行晶体结构优化,结果表明,W_(2)YZ系列合金均具有有序的Hg_(2)CuTi型立方晶体结构,其中W_(2)CoTe合金具有最低的总能量,结构更稳定。电子结构计算结果表明,该系列Heusler合金均表现为金属特征,不显示半金属或半导体特性。其中9种合金的总磁矩与总价电子数的关系符合M_(t)=Z_(t)-24的Slater-Pauling规则,而W_(2)MnSb,W_(2)FeSn,W_(2)FeSb,W_(2)FeTe,W_(2)CoSb和W_(2)CoTe这6种合金的磁矩稍偏离直线M_(t)=Z_(t)-24。

关键词： Heusler合金第一性原理电子结构磁性

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掺杂锂电池正极材料的第一性原理研究

杭州电子科技大学学报（自然科学版） 2022年第2期42卷 78-85页

作者：叶盼霍德璇陈许敏程杰胡旖航杭州电子科技大学电子信息学院浙江杭州310018

为提高Li_(2)MnSiO_(4)导电性和结构稳定性,采用第一性原理广义梯度近似GGA+U的方法,构建并分析Li_(x)Mn_(y)M_(1-y)SiO_(4)(x=2,1,0;y=0.5,1;M=Ni,Ti,Ce)结构的形成能、脱锂结构稳定性和电子态密度。研究发现,Li_(2)MnSiO_(4)的带隙为3.44 eV,导电性能差,掺杂结构Li_(2)Mn_(0.5)Ti_(0.5)SiO_(4),Li_(2)Mn_(0.5)Ce_(0.5)SiO_(4)和Li_(2)Mn_(0.5)Ni_(0.5)SiO_(4)分别呈现半导体特性、金属性和半金属性质,掺杂后导电性能得到改善。Li_(2)Mn_(0.5)Ti_(0.5)SiO_(4),Li_(2)Mn_(0.5)Ce_(0.5)SiO_(4)一次脱锂后的体积分别减小了8.05%和7.93%,脱锂相结构稳定性不足,而Li_(2)Mn_(0.5)Ni_(0.5)SiO_(4)一次脱锂后体积只减小2.98%,脱锂相结构较稳定,说明掺杂Ni是提升Li_(2)MnSiO_(4)导电性和结构稳定性的有效方法。

关键词：第一性原理 Li_(2)MnSiO_(4) 掺杂

基于能量法的施加预应力阶段CFRP布加固组合梁变形计算

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钢结构 2011年第1期26卷 34-36,78页

作者：霍君华王德选王连广东北大学资源与土木学院沈阳110004 沈阳建筑大学土木工程学院沈阳110168

为了改善CFRP布加固组合梁的受力性能,使CFRP布的抗拉强度得到充分利用,使用预应力CFRP布是一种有效的加固方法。结合加固组合梁结构的受力特性,在变分理论的基础上,利用能量法建立了施加预应力阶段的CFRP布加固组合梁变形的计算公式,... 详细信息

为了改善CFRP布加固组合梁的受力性能,使CFRP布的抗拉强度得到充分利用,使用预应力CFRP布是一种有效的加固方法。结合加固组合梁结构的受力特性,在变分理论的基础上,利用能量法建立了施加预应力阶段的CFRP布加固组合梁变形的计算公式,探讨了CFRP布弹性模量、胶结层剪切模量及胶结层厚度等因素对组合梁变形的影响。计算结果表明:组合梁跨中变形最大,由组合梁跨中向CFRP布端部呈非线性减小,CFRP布端部达到最小值,趋近于零;组合梁的变形随CFRP布弹性模量和胶结层厚度的增大而减小,随胶结层剪切模量的增大而增大。

关键词：预应力 CFRP布能量法组合梁变形计算