U型凹槽电极硅MSM结构光电探测器的研制

为了提高硅MSM结构光电探测器的光电响应度,制备了U型凹槽电极结构的探测器.5 V偏压下,对650 nm波长入射光的绝对光电响应度测试表明,凹槽电极结构的探测器最大光电响应度值为0.486 A/W,比同样尺寸的平版结构光电探测器提高了约6倍.文中也对比了具有抗反射膜和不具有抗反射膜的器件相对响应光谱的差别,并且比较分析了叉指间隙分别为5 μm和10 μm器件光电响应的不同.     

MSM光电探测器研究现状

由于金属－半导体－金属光电探测器潜在的优点，用于光通信、高速片到片互连、以及光控受到极大关注，文中介绍这种光探测器及其与放大器单片集成的最新进展。     

势垒层对黑硅光电探测器性能影响的研究

讨论势垒层Si3N4的引入对黑硅光电探测器光电性能的影响。探测器采用金属一半导体一金属（MSM）器件结构在黑硅层和电极间增加一层势垒层以提高肖特基势垒,从而减低器件的暗电流。实验表明,在相同的光照情况下,有势垒层的探测器暗电流比无势垒层的探测器暗电流至少低1个数量级,且势垒层厚度增加30nm其暗电流降低约1个数量级,而...     

光通信中的主流光电探测器研究

对光通信系统解复用接收部分中的关键器件——主流光电探测器进行综合比较、优缺点分析与展望．分别对PIN光电探测器,普通雪崩二极管,超品格雪崩二极管,波导型光电探测器,振腔增强型光电探测器,金属-半导体-金属光电探测器的原理和特点做了简要概括,并做系统比较,最后对光电探测器发展前景进行展望．     

GaAs基RTD与MSM光电集成

报道了GaAs基共振隧穿二极管(RTD)与金属-半导体-金属光电探测器(MSM PD)单片集成的两种光电集成电路,并在室温条件下分别测试了RTD器件、MSM器件和集成电路的电学特性.测试表明:RTD器件的峰谷电流比为4;由于改进了在半绝缘GaAs衬底上制作MSM的方法,5V偏压下的电流由原来的2μA增加到了18μA,基本实现了两种电路的逻辑功能.     

一种改进型金属-半导体-金属光电探测器数学模型

以E.Sano的金属-半导体-金属光电探测器(MSM-PD)模型为基础,提出了一种改进型的模型.该模型以多个电流源和电容并联的形式构造,以吸收区过剩电子和空穴总数为研究对象,求解速率方程.另外计算了电容,给出了暗电流与端电压的非线性计算式,改进了传统模型中暗电流的线性计算方法.通过线性叠加给出了该模型光电流的数学解析解.通过在Matlab中的模拟计算,表明该模型具有计算量小、准确度高的特点,它不仅能反映一定偏压和光照下光电流的变化,而且能展示光电子在器件中的转化过程.这种模型也能较好地应用于微弱信号的检测模拟.     

GaAs MSM结构光电探测器的光电特性研究

报导了作者研制的GaAs MSM—PD的直流及脉冲光电特性,对不同材料、不同结构尺寸的器件进行了试验和分析,测试结果:最大暗电流1.9nA,最高灵敏度为0.25A/W,FWHM小于110 ps(10V下),有较好的光电流和光功率线性关系,通过实验研究,发现对插指结构的器件在同一面积下受光面积与单位面积上的光电流存在最优化选择。     

In_(0.53)Ga_(0.47)As MSM光电探测器光电响应速度研究

本文通过分析In_(0.53)Ga_(0.47)As材料的电子漂移速度与电场的非线性关系,研究了In_(0.53)Ga_(0.47)As金属-半导体-金属光电探测器(MSM-PD)的光电响应与指状电极间距离、光吸收层杂质浓度及工作电压之间的关系。研究结果表明、光电响应速度存在最佳值。用计算机辅助分析得到的In_(0.53)Ga_(0.47)As MSM-PD的光电响应时间与偏置电压的关系与实验器件实测结果相一致。研究结果为设计高速响应In_(0.53)Ga_(0.47)As MSM-PD及建立器件光电响应模型提供了依据。     

MSM光电探测器电磁场特性的 TLM方法模拟

介绍了利用传输线矩阵方法模拟和分析金属－半导体－金属光电探测器的指栅电容的频率响应。应用时域电磁场三维TLM方法模拟分析了指栅间距和指栅间的耦合长度与光电探测器截止频率的关系。文中报道了本项研究所开发的三维电磁场时域模拟器TLM Simulator2.0及其功能。数值实验结果说明模拟器对微波结构的电磁场模拟是精确、有效的,具有很好的应用价值。     

长波长低暗电流高速In_(0.53)Ga_(0.47)As MSM光电探测器

本文首次介绍了用低温MOVPE技术,研制成功具有非掺杂InP 肖特基势垒增强层的InCaAs金属-半导体-金属光电探测器(MSM-PD).其暗电流在 1.5伏下小于 60 nA(100 ×100)微米~2;响应时间t_r小于30 ps(6伏).其灵敏度在6 V下为0.42 A/W.     

溶胶-凝胶提拉法制备Mg_xNi_(1-x)O薄膜与表征

利用溶胶凝胶提拉法在石英玻璃衬底上制备出吸收边波长位于地球表面太阳光谱日盲区(240～280nm)内的MgxNi1-xO薄膜.XPS和XRD结果显示,MgxNi1-xO在1000℃下形成具有立方结构的固溶体;紫外可见吸收谱结果表明,MgxNi1-xO吸收边随着Mg含量的变化而发生改变,当Mg含量x在0.2～0.3之间时,薄膜的吸收边波长在248～276nm范围内可调;光电响应测试结果表明,MgxNi1-xO薄膜(x=0.3)对太阳光不敏感,而对波长为254nm的紫外光具有很好的光电导特性,光照前后薄膜电阻变化率达40%,因此,我们可以认为MgxNi1-xO(x=0.2～0.3)薄膜材料有望应用于日盲区的紫外探测.     

Ultraviolet-visible metal-semiconductor-metal photodetectors fabricated from InxGa1−xN (0≤x≤0.13)

Metal-semiconductor-metal (MSM) photodetectors have been fabricated on In_xGa_1−xN epitaxial films grown by metalorganic chemical vapor deposition within the composition range 0≤x≤0.13. The dark current and spectral response were measured for devices with a varying In mole fraction x. The devices, which had nominal finger widths and finger spacing of 5 μm, were biased with modest voltages in the range 2≤V_bias≤5 V. In general, turn-on wave-length and dark current increased with increasing x. Turn-on wavelengths ranged from λ=370 nm to 430 nm and dark current densities ranged from I_dark=2×10⁻² A/cm² (V_bias=5 V, x≈0.05) to 9×10⁴ A/cm² (V_bias=2 V, x≈0.13) depending on the In content, x, of the device active area.     

基于微型谐振腔的环形光探测器设计

提出了一种基于微型谐振腔的新型环形光探测器(MRPD),MRPD采用谐振腔和吸收腔分离的结构.MRPD避免了直波导与环形腔完全耦合时限制因子极低的问题,具有更强的可行性.导出了量子效率的表达式,分析了量子效率与谐振腔半径的关系及透射系数与光谱半高全宽(FWHM)的关系.     

InxGa1−xAs (x=0.25–0.35) grown at low temperature

In_xGa_1−xAs (x=0.25–0.35) grown at low temperature on GaAs by molecular beam epitaxy is characterized by Hall effect, transmission electron microscopy, and ultrafast optical testing. As with low temperature (LT) GaAs, the resistivity is generally higher after a brief anneal at 600°C. High-resolution transmission electron microscopy shows all the as-grown epilayers to be heavily dislocated due to the large lattice mismatch (2–3%). When the layers are annealed, in addition to the dislocations, precipitates are also generally observed. As with LT-GaAs, the lifetime shortens as growth temperature is reduced through the range 300–120°C; also, the lifetime in LT-In_xGa_1−xAs is generally shorter in as-grown samples relative to annealed samples. Metal-semiconductor-metal photodetectors fabricated on the material exhibit response times of 1–2 picoseconds, comparable to results reported on GaAs grown at low temperature, and the fastest ever reported in the wavelength range of 1.0–1.3 μm.     

Metal-semiconductor-metal (MSM) photodetectors fabricated on MOCVD grown Hg/sub 1-x/Cd/sub x/Te

The fabrication of the first metal-semiconductor-metal photodetectors on Hg/sub 1-x/Cd/sub x/Te is reported using MOCVD grown layers on GaAs substrates. An epitaxial CdTe overlayer has been incorporated in the device structure for the enhancement of Schottky barrier characteristics. The interdigitated devices (2.3 mu m electrode width, 3.3 mu m spacing) exhibited a breakdown voltage of -60 V and responsivities of more than 1.0 A/W at a wavelength of 1.3 mu m and bias voltage of 40 V. Over the range of bias voltage examined, the dark leakage current of the detectors was dependent on the choice of contact metal, with minimum values of 10 nA at <1 V for Pt/CdTd/Hg/sub 1-x/Cd/sub x/Te.<>     

Zn(MgBe)Se ultraviolet photodetectors

We present the growth and characterization of blue-violet and ultraviolet photodetectors based on ZnSe and Zn(Mg)BeSe compounds. Structures are grown by molecular beam epitaxy on (001) GaAs substrates. Three types of photodetectors have been fabricated. Zn(Mg)BeSe p-i-n photodiodes exhibit a high response of 0.17 A/W with a rejection rate of 10⁴ and a wavelength cutoff of 450 nm. Schottky barrier photodiodes based on planar geometry devices display a very flat response above the band gap with a rejection rate above 10³. High responses with quantum efficiency higher than 50% have been obtained. The wavelength cutoff can be tuned from 460 (ZnSe) to 380 nm (ZnMgBeSe), which leads to visible blind devices. Detectivities from 2.0 10¹⁰ (ZnMgBeSe) to 1.3 10¹⁰ mHz^1/2W⁻¹ (ZnSe) have also been measured. Metal-semiconductor-metal devices, recently fabricated, exhibit a spectral response very similar to Schottky devices. Quantum efficiencies of 40% are easily obtained in these devices with a rejection rate of 10³.     

Effect of dimensional parameters on the current of MSM photodetector

In this work, we present the influence of dimensional parameters on dark current and photocurrent of the metal-semiconductor-metal photodetector (MSM). MSM photodetectors of different sizes have been fabricated on GaAs (NID). The active area of MSM samples varies between 1×1 μm² and 10×10 μm² with equal electrodes spacing and finger widths (l=D) varying between 0.2 and 1 μm. The I(V) characterization in inverse and direct polarization in darkness shows good symmetry of curves, which shows the good performance of components and successful fulfillment of the Schottky contacts. The application of laser fiber of incident light power of 16 mW at wavelength of 850 nm for the illumination of the MSM photodetectors showed the evolution of the photocurrent ranging from 0.75 to 1.81 mA, respectively, for 1 to 0.2 μm electrodes spacing at 3 V and active area S=3×3 μm². We showed also that variation ranging from 0.45 to 2.5 mA, respectively, for S=1×1 μm² to S=10×10 μm² at 3 V and 0.3 μm electrodes spacing. The resistance of MSM photodetectors obtained evolved proportionally to the electrodes spacing (0.87 kΩ for D=0.2 μm and 2.27 kΩ for D=1 μm with S=3×3 μm²) and inversely proportional to the surface area (2.02 kΩ for S=1×1 μm², and 0.56 kΩ for S=10×10 μm² with 0.3 μm inter electrodes spacing).     

弛豫型铁电陶瓷(1-x)Pb(Sc1/2Ta1/2)O3-xPbTiO3研究进展

钽钪酸铅陶瓷具有优良的介电、压电和铁电性能,但烧成温度高、居里点较低。为降低钽钪酸铅陶瓷的烧结温度并提高其居里点,人们合成了钽钪酸铅-钛酸铅(简称PSTT)材料体系。该文综述了弛豫型铁电陶瓷PSTT体系在相图与结构、制备和性能等方面的研究进展,探索了一种合成PSTT陶瓷新工艺,介绍了PSTT材料体系的重要应用领域。