现代半导体材料越来越多地用于多学科系统中,展示了机械应变和电子势之间的交叉相互作用,这使得高灵敏度,自供电传感器设备中的应用无处不在。这种半导体材料表现出压电性能的基本前提之一是晶体结构的非中心对称性。$β$ -Ga $_2$ O $_3$由于其超宽带隙而成为一种新兴的化合物半导体材料。然而,原始的$β$ -Ga $_2$ O $_3$具有反转中心,没有显示出压电效应.本工作利用第一性原理方法发现,替位掺杂的$β$ $_2$ O $_3$具有压电性质,而以往对其替位掺杂的研究主要集中在提高电导率和形成半导体异质结方面。更有趣的是,它是从这项工作揭示了形成能有一个明确的关系与压电系数。
英文摘要:
Modern semiconductor materials are increasingly used in multidisciplinary systems demonstrating cross-interactions between mechanical strains and electronic potentials, which gives rise to ubiquitous applications in high sensitivity, self-powered sensor devices. One of fundamental prerequisites for such semiconductor materials to exhibit piezoelectric properties is the noncentrosymmetry of the crystal structures. $β$-Ga$_2$O$_3$ has been an emerging compound semiconductor material due to its ultra-wide bandgap. However the pristine $β$-Ga$_2$O$_3$ has an inversion center, displaying no piezoelectric effect. This work discovered that substitutionally doped $β$-Ga$_2$O$_3$ possesses piezoelectric property by using first principles method, while majority of previous research on its substitutional doping has been focusing on the purposes of increasing electrical conductivity and formation of the semiconductor heterojunctions. More interestingly, it is unveiled from this work that the formation energy has a clear relation with the piezoelectric coefficient.
Defect-Engineered Multifunctionality in Cu-Doped Bi2Te2: Interplay of Thermoelectric, Piezoelectric, and Optoelectronic Properties from First-Principles Insights
University of West Bohemia(西波希米亚大学);Riphah International University(里帕赫国际大学);Northern Border University(北部边界大学)
Spin-dependent ballistic transport properties and electronic structures of pristine and edge-doped zigzag silicene nanoribbons: large magnetoresistance
Vanadium-Engineered Co2NiSe4 Nanomaterial: Coupled Thermoelectric, Piezoelectric, and Electronic Optimization via DFT+U for Advanced Energy Applications
Solution-Based Fabrication of High-Performance K$_{0.5}$Na$_{0.5}$NbO$_3$ Thin Films for Surface Haptics
Luxembourg Institute of Science and Technology(卢森堡科学与技术研究所);University of Luxembourg(卢森堡大学);Jožef Stefan Institute(约瑟夫·斯特凡研究所);Kyungpook National University(庆北国立大学);Harbin Engineering University(哈尔滨工程大学);Technische Universität Darmstadt(达姆施塔特工业大学)
Systemic Consequences of Disorder in Magnetically Self-Organized Topological MnBi$_{2}$Te$_{4}/$(Bi$_{2}$Te$_{3}$)$_{n}$ Superlattices
MnBi $_{2}$ Te $_{4}/$(Bi $_{2}$ Te $_{3}$)$_{n}$材料系统作为实现量子反常霍尔(QAH)态的天然平台最近引起了强烈的兴趣。该系统在磁性上比替代掺杂的材料更好地有序,然而,某些无序的有害影响正变得越来越多地被承认。在这里,通过编译铁磁MnBi $_{2}$ Te $_{4}/$中无序的结构、成分和磁性度量,(Bi $_{2}$ Te $_{3}$)$_{n}$发现Mn在MnBi $_{2}$ T $e_{4}$七重层(SL)和其它非磁性Bi $_{2}$ Te $_{3}$五重层(QL)之间的迁移具有系统性后果-它引起Mn耗尽SL与Mn掺杂QL的铁磁耦合,在铁磁共振中被看作是两个耦合自旋子系统的声学和光学共振模式。即使对于大的SL分离(n $\gtrsim$ 4个QL),该结构也不能被认为是非耦合二维层的堆叠。角分辨光电子能谱和密度泛函理论的研究表明,在SL中的Mn无序导致电子波函数的离域和表面能带结构的变化相比,理想的MnBi $_{2}$ Te $_{4}/$(Bi $_{2}$ Te $_{3}$)$_{n}$。这些研究结果突出了SL间和SL内无序对实现新的QAH平台以及探索内在拓扑磁体中的新型轴子物理的至关重要性。
Acoustic phonon limited mobility in two-dimensional semiconductors: Deformation potential and piezoelectric scattering in monolayer MoS2 from first principles
利用Boltzmann方程和声学电子-声子(el-ph)相互作用的第一性原理计算,对温度T < 100 K和高载流子密度下n掺杂二维MoS 2中的声学声子有限迁移率进行了理论研究.结合连续介质弹性模型,建立了变形势与压电相互作用的解析表达式和耦合强度。此外,我们表明,变形势相互作用的贡献,从正常和umklapp过程,后者的贡献只有微弱的影响,载流子屏蔽。因此,计算出的迁移率显示出从高温μT^{-1}行为到低温Bloch-Gruneisen区域中更强的μT^{-4}行为的转变,该区域是未屏蔽变形势散射的特征。在T < 10 K和高载流子密度(n > 10^{11} cm^{-2})下,本征迁移率预计超过10^5 cm ^2 V^{-1} s^{-1}。在100 K时,迁移率不超过~7 x 10^3 cm 2 V^{-1} s^{-1}。我们的研究结果提供了新的和重要的理解声学el-ph相互作用和它的屏蔽自由载流子,并在一般的声学声子有限迁移率的理解是高度相关的。
Improvement of piezocatalytic performance of Na0.5Bi0.5TiO3 perovskite using K doping for efficient Rhodamine B degradation
Cadi Ayyad University, Faculty of Sciences and Technology(卡迪·阿亚德大学科学技术学院);University of Picardie Jules Verne(皮卡第朱尔·凡尔纳大学);University of Bordeaux(波尔多大学);Univ Lorraine, CNRS, IJL(洛林大学、法国国家科学研究中心、界面与实验室联合研究单位);Jožef Stefan Institute(约瑟夫·斯蒂芬研究所);Mohammed VI Polytechnic University(穆罕默德六世理工学院)