碲镉汞光导探测器的变温测试

报道了ＨｇＣｄＴｅ光导探测器光电参数随温度变化的关系，重点描述了光谱响应变温测试，给出了ＨｇＣｄＴｅ器件从液氮到室温 之若干个不同温度点测试的光谱响应曲线及器件变温测试的性能参数对照表，并与经验公式计算结果进行对比，给出了相应的测试误差分析。     

碲镉汞材料提纯研究

杂质是影响碲镉汞器件性能的重要因素之一.对于碲锌镉衬底晶体和窄禁带碲镉汞材料来说,杂质的影响更加显著.主要论述了碲镉汞材料中常见的杂质类型以及杂质在材料中的作用,并分析了影响器件性能的主要杂质.采用辉光放电质谱法(Glow Discharge Mass Spectrometry,GDMS)测试了材料中的杂质含量,同时通...     

碲镉汞光导探测器的性能

本文分析了探测器长度对Hg_(1-x)Cd_xTe光导探测器性能的影响。分析是针对工作在77～300K温度范围3～5μm和8～14μm波段的器件进行的。将由几个厂商制造的探测器的实验数据与基于Rittner模型及我们为有阻挡接触点的光导器件开创的理论研究所做的理论预测进行了比较。力图阐明理论与实验结果之间的差异。     

长波碲镉汞材料的低温退火

本文分析和讨论了碲镉汞材料退火的微观机制和退火条件，根据分析的结果对加速旋转坩埚技术布里奇曼法生长的长波碲镉汞材料进行了低温退火实验，取得了满意的结果。对于０．７ｍｍ厚的样品，１９０～２２０℃下汞饱和等温退火５０～６０天可获得电学性能优良的ｎ型材料。７７Ｋ下载流子浓度ｎ＜５×１０１４ｃｍ－３，载流子迁移率μ＞１×１０５ｃｍ２／Ｖ·Ｓ，少子寿命τ＞１μｓ。     

碲镉汞薄膜的MOVPE生长和特性

报道了在水平、常压ＭＯＶＰＥ实验型生产装置中,采用互扩散多层工艺（ＩＭＰ）,用金属有机化合物ＤＭＣｄ、ＤｉＰＴｅ和元素Ｈｇ,在ＣｄＴｅ和ＧａＡｓ衬底上生长的ＨｇＣｄＴｅ薄膜,其组分和薄膜厚度的均匀性以及ｐ型电学性质,初步达到了目前红外焦平面列阵研制的要求,同时,这种薄膜的生长具有一定重复性。     

用椭圆偏振测量法分析碲镉汞的组分及其均匀性

简略介绍了椭偏仪的测量原理和测量装置。分析了Hg1-xCdxTe(MCT)的 组分与椭偏仪的参数Δ和ψ之间的关系,结果发现碲镉汞的组分x主要与椭偏仪的参数ψ有关,而且x与ψ的经验关系为ψ＝14．84－10.22x。最后椭圆偏振测量的方法分析了碲镉汞的横向和纵向组分均匀性。该方法具有非破坏性、有效、快捷的特点。     

Hg1-xMnxTe的光学性质研究

根据Hg1-xMnxTe的光学吸收光谱，用Kana模型详细分析了重空穴和导带间的直接跃迁导致的本征光吸收。研究表明当光吸收系数α<103 cm-1时，在导带中没有出现从抛物线色散规律引起的偏离，因而保证了Hg1-xMnxTe带宽的精确确定。     

霍尔效应和霍尔传感器的教学方法研究

磁电效应(电磁感应、霍尔效应、磁致电阻效应)是磁场与物质之间的重要的物理效应。只有深入理解电磁学原理,才能进一步学好霍尔传感器。本文针对现有教材状况,强调从理解电磁学中带电粒子在磁场、电场中的运动规律开始,进而深入学习霍尔效应和霍尔传感器。本文还介绍了用形象生动的教学方法,使学生扎实牢固地掌握该知识。     

0.3K下的GaAs/Al_xGa_(1-x)As异质结中的分数量子霍耳效应

本文从实验上比较了低浓度 GaAs/Al_xGa_(1-x)As异质结样品在4.2K、1.3K和0.34K 温度下的整数量子霍耳效应,报道了填充因子v=2/3的分数量子霍耳效应的实验观察结果.讨论了低浓度GaAs/Al_xGa_(1-x)As样品中宏观不均匀性对实验结果的影响.     

Photoquantum Hall Effect and Light‐Induced Charge Transfer at the Interface of Graphene/InSe Heterostructures

The transfer of electronic charge across the interface of two van der Waals crystals can underpin the operation of a new class of functional devices. Among van der Waals semiconductors, an exciting and rapidly growing development involves the “post‐transition” metal chalcogenide InSe. Here, field effect phototransistors are reported where single layer graphene is capped with n‐type InSe. These device structures combine the photosensitivity of InSe with the unique electrical properties of graphene. It is shown that the light‐induced transfer of charge between InSe and graphene offers an effective method to increase or decrease the carrier density in graphene, causing a change in its resistance that is gate‐controllable and only weakly dependent on temperature. The charge transfer at the InSe/graphene interface is probed by Hall effect and photoconductivity measurmentes and it is demonstrated that light can induce a sign reversal of the quantum Hall voltage and photovoltaic effects in the graphene layer. These findings demonstrate the potential of light‐induced charge transfer in gate‐tunable InSe/graphene phototransistors for optoelectronics and quantum metrology.     

某剧场夏季座椅送风气流组织的测试分析

近年来对置换通风的研究越来越多,但大多局限于数值模拟,针对一实际工程,测试了剧场内座椅送风条件下观众附近的空气温度和流速,分析了测试结果,结果是座椅送风气流组织的空气流速比较小,气流造成的不舒适感小,但是由于设计中考虑的不全面,出现了南北侧温差大,楼座池座温差大的缺点。     

基于霍尔效应的微波功率线性测量技术研究

为了提高微波功率测量的准确性,文中将平面电磁波作用于霍尔器件,用解析方法得到了霍尔电压的直流分 量与微波功率密度之间的线性关系。基于同轴线设计了通过式与吸收式两种型号的微波功率探测器。以同轴通过式 为例,在0.1 mW~50.0 mW 的微波功率测量范围内,探测器的线性度达98.28%,瞬态响应时间为3 μs~6 μs,频率响应 范围为1 GHz~10 GHz。实验结果与理论分析结果一致,该新型探测器具有线性度好和响应速度快的特点,有望得到更 为广泛的应用。     

Observation of Colossal Topological Hall Effect in Noncoplanar Ferromagnet Cr5Te6 Thin Films (Adv. Funct. Mater. 33/2023)

The topological Hall effect (THE) is critical to the exploration of the spin chirality generated by the real-space Berry curvature, which has attracted worldwide attention for its prospective applications in spintronic devices. However, the prominent THE remains elusive at room temperature, which severely restricts the practical integration of chiral spin textures. Here, a colossal intrinsic THE is showed up to ≈1.6 µΩ cm in large-area ferromagnet Cr₅Te₆ thin films epitaxially grown by pulsed laser deposition. Such a THE can be maintained until 270 K, which is attributed to the field-stimulated noncoplanar spin textures induced by the interaction of the in-plane ferromagnet and antiferromagnet infrastructures. The first-principles calculations further verify the considerable Dzyaloshinskii-Moriya interaction in Cr₅Te₆. This work not only paves the way for robust chiral spin textures near room temperature in large-area low-dimensional ferromagnetic films for practical applications, but also facilitates the development of high-density and dissipationless spintronic devices.     

SiO_x、Si/Si_(1-x)Ge_x的横向磁阻和迁移率的无接触测量

用分子束外延技术在ｐ型Ｓｉ衬底上生长成了Ｓｉ／Ｓｉ１－ｘＧｅｘ应变层超晶格和掺铒（Ｅｒ）ＳｉＯｘ外延层,用无接触法测量了它们的横向磁阻,并且用拟合方法由横向磁阻计算了它们的迁移率。     

霍尔传感器的应用探讨

简要介绍了霍尔元件的基本应用,对霍尔元件的选用原则进行了探讨,对霍尔元件实际应用过程所用到的典型放大电路进行了较为详尽的描述;还探讨了霍尔元件技术指标不等位电势的测量方法,并对霍尔元件直流激励情况下位移测量的方法进行了讨论,以霍尔元件实际应用的个例扩展到霍尔元件的广泛应用。     

Electrical and surface composition properties of phosphorus implantation in Mg-doped GaN

Changes in electrical as well as surface composition such as chemical and electronic properties of Mg-doped p-type GaN by phosphorus implanting are systematically investigated using Hall effect and X-ray photoelectron spectroscopy (XPS) measurements. It is shown that p-type conductivity of Mg-doped GaN can be improved by implanting P atoms after a proper post-implantation annealing treatment, probably due to the reduction of self-compensation by P atoms substitution on N vacancy sites. XPS analysis is further found that the decrease of surface oxides and the shift of the surface Fermi level toward the valence band edge through P atoms introduced. These experimental results indicate that the P implantation is an effective method to improve p-type conductivity of Mg-doped GaN and reducing the surface barrier height, which can lead to a lower metal contact resistivity to p-type GaN.