Development of a novel high speed (electron-mobility) epi-n-ZnO thin films by L-MBE for III–V opto-electronic devices

Intrinsic epitaxial zinc oxide (epi-ZnO) thin films were grown by laser-molecular beam epitaxy (L-MBE), i.e., pulsed laser deposition (PLD) technique using Johnson Matthey “specpure”-grade ZnO pellets. The effects of substrate temperatures on ZnO thin film growth, electrical conductivity (σ), mobility (μ) and carrier concentration (n) were studied. As well as the feasibility of developing high quality conducting oxide thin films was also studied simultaneously. The highest conductivity was found for optimized epi-ZnO thin films is σ=0.06×10³ ohm⁻¹ cm⁻¹ (n-type) (which is almost at the edge of semiconductivity range), carrier density n=0.316×10¹⁹ cm⁻³ and mobility μ=98 cm²/V s. The electrical studies further confirmed the semiconductor characteristics of epi-n-ZnO thin films. The relationship between the optical and electrical properties were also graphically enumerated. The electrical parameter values for the films were calculated, graphically enumerated and tabulated. As a novelty point of view, we have concluded that without doping and annealing, we have obtained optimum electrical conductivity with high optical transparency (95%) for as deposited ZnO thin films using PLD. Also, this is the first time that we have applied PLD made ZnO thin films to iso-, hetero-semiconductor–insulator–semiconductor (SIS) type solar cells as transparent conducting oxide (TCO) window layer. We hope that surely these data be helpful either as a scientific or technical basis in the semiconductor processing.     

BOUNDARY AND CORNER LAYER BEHAVIOR IN SINGULARLY PERTURBED ROBIN BOUNDARY VALUE PROBLEM

This paper is concerned with boundary and corner layer behavior of the singularly perturbed Robin boundary value problem(RP) for the second-order nonlinear differential equations. The existence and asymptotic estimate of solutions of (RP) is discussed by appropriately constructing the bounding functions and using the theory of differential inequality.     

薄层流中的一类三阶奇摄动边值问题的渐近分析

本文研究薄层流中出现的一类三阶奇摄动数学模型．本文不采用研究其渐近等价的二阶奇摄动微分方程的方法,而利用边界层函数法,直接讨论该数学模型的渐近解,并严格地证明了解的存在唯一性和其渐近解的一致有效性．本文的结果不仅去掉了以往方法所必须的位势条件,纠正了某个不适定的假设,而且推广了以往的结果．     

Effects of shaded facets on the performance of metal-coated etched diffraction grating demultiplexer

A finite-difference time-domain (FDTD) method combined with a periodic boundary condition is used to analyze the diffraction efficiency of an etched diffraction grating (EDG) demultiplexer coated with a metallic film at the backside. The numerical results show that the diffraction loss is mainly due to the scattering effect of shaded facets of a metal-coated grating at both the polarizations. However, the same shaded facets can produce a higher loss for a TM polarization than that for a TE polarization, which induces a higher polarization dependent loss (PDL) of the demultiplexer.     

用硅双结型色敏器件测量色温

提出了一种用硅双结型色敏器件测量色温的方法．在合理的测控电路下，硅双结型色敏器件的电流对数比与实验灯泡的色温值呈良好的单值对应，经单片机处理后可以得到分段线性关系．通过对电流对数比与波长随线的数据拟合，结果表明，用硅双结型色敏器件测量色温，其测量温度可以到10^4K以上，精度可以达到10K．本文的方法与传统方法相比减少了工作量，降低了费用，具有通用性和实用价值．     

Layered Double Hydroxide as Cordycepin Delivery Nanocarrier

Layered double hydroxides (LDHs), also called “anionic clays”, have received considerable attention due to their technological importance in catalysis, adsorption, optics, nanocomposite engineering materials and medical science1-5. LDHs are layered mate…     

Three Dimension Simulation of Millimeter Wave Double Staggered Coupled Cavity Structure

After analyzed the cavity field mean method theory resolution, the software simulation method to obtain the resonance frequency, Q value and RF dispersion by MAFIA and ANSYS software is discussed for the double staggered coupled cavity Millitron structure in the millimeter-wave TWT. The resonance frequency and Q value of the single cavity is obtained and is consistent with two kind of the simulation software. Their average error is about 0.6%. The two kind of the simulation result is consistent to the design precise. The simulation method saves on the cost and time in the experiment, improve the data precise and work efficiency. The trend of the dispersion simulation result is consistent with the cavity field mean method theory result. The high end of the theory result is great contrast to that of MAFIA result. It shows that the theory adopt some hypothetical conditions, But the theory result has some instructional signification in initialization design of the novel slow wave structure.     

包层泵浦的L波段Er3+/Yb3+共掺光纤激光器

报道了一种工作波长在L波段的包层泵浦Er³⁺/Yb³⁺共掺光纤环形激光器. 环形腔内的激光工作介质为一段9 m长的Er³⁺/Yb³⁺共掺高掺杂光纤. 利用6个976 nm LD同时抽运前段Er³⁺/Yb³⁺共掺双包层光纤产生的放大自发辐射谱作二次抽运源, 使腔内增义谱由C波段移到L波段, 实现了L波段光纤激光器的稳定输出; 采用包层泵浦技术, 在抽运功率为3594.5 mW时, 测得泵浦入纤功率为2731.8 mW, 实现了输出连续功率最大518.4 mW,斜率效率达到19% 的激光输出; 所形成激光的工作波长为1613.94 nm, 激光光谱的3 dB带宽为1.5 nm, 边模抑制比接近于50 dB.     

12参双参数矩形板元的误差估计

双参数方法是构造高阶问题有限元的有效方法．以此方法构造的双参数元是一种非标准元，以往文献中只证明了它的收敛性．此文针对具体12参双参数矩形板元给出它的误差估计式，并分析了节点参数的扰动量．文中的分析方法也适合于其它双参数矩形板元的误差估计．