温度对图形化蓝宝石透过率性能影响研究

蓝宝石单晶表面图形化作为一种全新的减反增透手段而受到广泛关注,然而在服役过程中其透过率将会由于温度的改变而发生变化,影响使用性能.本文通过高温红外光谱测试系统测试了图形化蓝宝石在25℃,300℃,400℃,500℃,600℃时3～6 μm波段范围内的透过率,分析了温度对图形化蓝宝石透过率性能的影响.分析表明,表面图形化使室温条件下蓝宝石透过率在一定波段范围内上升且伴随有明显的光谱红移效应;温度上升使图形化蓝宝石透过率下降且红移现象加剧,随着温度不断升高蓝宝石透过率有一定程度回升;高温条件下表面图形化对蓝宝石透过率的影响不是十分明显.     

蓝宝石衬底材料的研究及应用进展

蓝宝石因为其生产技术成熟、稳定性好、性价比高而被广泛应用于光电领域,成为GaN基光电器件的主要衬底材料.传统的蓝宝石衬底生长GaN薄膜存在许多问题,如由晶格常数不同产生的晶格失配、热应力失配等,且GaN薄膜结晶质量较差、光线提取效率低.介绍了图形化蓝宝石衬底技术在制作GaN基LED器件中的应用,比较了几种图形化衬底对LED的发光性能的影响.在图形化蓝宝石衬底上采用PVD法生长AlN薄膜,可以降低GaN薄膜的螺旋位错和刃位错、提高MOCVD生长效率、显著提高设备利用率.另外,介绍了蓝宝石衬底在SOS领域的应用,列出了SOS工艺对蓝宝石衬底的具体要求.蓝宝石作为一种重要的衬底材料,未来的发展前景会更加广阔.     

镁/钛离子注入对蓝宝石微结构和机械性能的影响

离子注入已被证明是改善蓝宝石光学和机械表面性能的一种可靠方法.本文选择不同能量和剂量的镁/钛离子注入蓝宝石.利用TRIM(Transport of Ion Matter)程序分析了镁/钛离子在蓝宝石晶体中的射程分布.利用拉曼光谱和掠入射X射线衍射分析了损伤层深度和微结构变化.离子注入结果显示,蓝宝石的纳米硬度、纳米划痕和红外性能等均呈现出可调节的特性.     

镁/钛离子注入对蓝宝石微结构和机械性能的影响（英文）

离子注入已被证明是改善蓝宝石光学和机械表面性能的一种可靠方法。本文选择不同能量和剂量的镁/钛离子注入蓝宝石。利用TRIM (Transport of Ion Matter)程序分析了镁/钛离子在蓝宝石晶体中的射程分布。利用拉曼光谱和掠入射X射线衍射分析了损伤层深度和微结构变化。离子注入结果显示,蓝宝石的纳米硬度、纳米划痕和红外性能等均呈现出可调节的特性。     

蓝宝石单晶纳米压痕蠕变性能研究

蓝宝石单晶的蠕变性能对结构失效行为有很大的影响.本文采用纳米压痕测试方法对蓝宝石单晶窗口材料的蠕变性能进行了测试与分析.分析表明,纳米压痕测试方法能够较为精确地测得蓝宝石单晶蠕变应力指数;不同的最大载荷对蓝宝石单晶的蠕变位移及蠕变应力指数没有明显的影响;蓝宝石单晶的蠕变位移及蠕变应力指数随着加载速率的减小分别减小和增大.     

飞秒脉冲激光对蓝宝石辐照作用的研究

本文采用脉冲宽度为120fs,波长为800nm的飞秒激光对蓝宝石样品进行辐照,经过激光辐照后材料呈暗黑色,在辐照区域的边缘发现有微裂纹,个别区域以至于微裂纹扩展成宏观裂纹.通过相关数学模型计算出激光聚焦后能量密度、蓝宝石在激光辐照瞬间的热影响范围(HAZ)及材料所达到的最高温度.发现经飞秒激光辐射引起样品的附加吸收与波长呈指数衰减关系.材料在经过飞秒激光辐射照后出现了大量的红外吸收峰,并对其产生原因进行了分析.     

红外窗口和整流罩材料研究现状与发展趋势

介绍红外窗口的三个综合性能评价因子:热破裂品质因子、光畸变品质因子、抗热冲击品质因子;并用它们评价了氟化镁、尖晶石、氮氧化铝、蓝宝石、硫化锌和硒化锌、金刚石等主要的红外窗口和整流罩材料;综述其国内外的研究现状,并对其未来的发展趋势发表了自己的观点.     

热屏间距对泡生法蓝宝石单晶生长影响研究

太空、军事和科研等高科技领域的持续发展极大促进了对蓝宝石晶体的需求,泡生法是蓝宝石晶体的主要制造方法之一;热场结构对所得蓝宝石晶体的质量具有重要影响.本文对采用泡生法工艺制造蓝宝石单晶过程中,具有内置7层氧化锆外置8层钼金属的新型热屏结构间距进行研究.通过数值模拟考察热屏间距对单晶炉功率、固-液界面形状和晶体热应力的影响确定了合理的热场结构;并与试验生产结果进行对比验证.结果表明:热屏间距增大使得单晶炉功率明显提升,并引起固-液界面凸度增大;而蓝宝石晶体热应力出现减小.综合考察三个影响因素的影响,最后确定热屏间距为5 mm时单晶炉能耗较低,可用于制造高质量的蓝宝石晶体.     

蓝宝石单晶窗口材料空间粒子辐照效应研究

蓝宝石单晶(α-Al2O3)窗口材料服役于空间环境中将不可避免地受到各种不同射线及离子流的辐照作用,影响其使用性能.本文研究了蓝宝石单晶经不同剂量质子流、电子流以及综合流辐照后其表面粗糙度、透过率以及面形精度等光学性能和结构的变化.实验表明空间粒子辐照使蓝宝石表面粗糙度增大且具有剂量效应,其中综合流对表面粗糙度影响最大,质子次之,电子影响最小;UV-Vis-VIR及FTIR测试实验表明空间粒子辐照使蓝宝石透过率下降,在紫外波段下降最明显,且在不同波段范围内不同辐照粒子种类对蓝宝石单晶透过率的影响程度也不同;粒子辐照对面形精度的影响不明显.     

泡生法不同轴向蓝宝石的生长和光谱特性研究

应用自行研发的泡生法蓝宝石设备生长了a向及c向蓝宝石晶体,测量了它们的吸收光谱、摇摆曲线,采用KOH腐蚀并观察了两种不同生长方向的晶体缺陷,对两种不同生长方向晶体缺陷的差异进行了分析.结果表明采用a向籽晶生长的蓝宝石晶体透过率略优于c向籽晶生长的晶体,a向生长晶体晶格完整性高于c向生长晶体,c向生长的蓝宝石晶体位错密度明显高于a向生长的蓝宝石晶体.     

Large-size oxyfluoride glasses used for vis–IR-transmitting windows

Windows for infrared sensors on missiles, aircraft and high energy laser systems must be of excellent spectral properties, high optical quality, large and durable enough to protect delicate sensors from harsh operating conditions. This paper describes work being done for IR window applications on heavy metal oxyfluoride (HMOF) glasses, which provide a combination of infrared transparency, strength, hardness, and environmental stability in a largely-sized formable material, and represents potential candidate materials for infrared windows.     

基于锑化物二类超晶格的多色红外探测器研究进展

近年来InAs/GaSb二类超晶格红外探测器在材料晶体结构生长、器件结构设计与成像应用方面取得了飞速发展。尤其在多色红外探测方面,二类超晶格材料以其具备的带隙可调、暗电流小、量子效率高、材料均匀性高,以及成本低等优越性能,使其逐步成为第三代红外焦平面探测器的优选材料。本文阐述了锑化物窄带隙半导体研究中心的锑化物多色红外探测器研究进展。本团队成功实现了低噪声、高量子效率以及低光学串扰的短/中、短/长、中/长、长/长、中/长/甚长波等多种高性能多色红外探测器研制。     

Study of Te inclusions in CdMnTe crystals for nuclear detector applications

The concentration, size and spatial distribution of Te inclusions in the bulk of CdMnTe crystals mined from two batches of ingots were studied. An isolated planar layer decorated with Te inclusions was identified in CdMnTe crystals from the second ingot. The internal electric field of a CMT crystal was probed by infrared (IR) imaging employing Pockels electro-optic effect. The effect of an isolated plane of Te inclusions on the internal electric-field distribution within the CdMnTe crystal was studied. Space charge accumulation around the plane of Te inclusions was observed, which was found to be higher when the detector was reverse-biased. The effects of the plane of Te inclusions on the electric-field distribution within the CdMnTe crystal, and the quality of CdMnTe crystals for nuclear detector applications are discussed.     

锑化铟晶体材料的发展及应用

锑化铟(InSb)晶体材料自发现伊始,基于其独特的物理化学性质和优良的工艺兼容性,成为了半导体材料领域研究的热点。近几十年来,由于其在红外探测领域的应用前景,更是深受国内外研究机构的广泛关注和重视,技术发展迅速。目前,InSb晶体材料作为制备高性能中波红外探测器的首选材料,应用前景和商业需求巨大,基于InSb晶体材料的红外探测器的快速发展更是大大提升了红外系统的性能,促进了红外技术在军民领域的广泛应用。本文主要介绍了InSb晶体材料的性质,梳理了国内外各公司及研究机构关于InSb晶体材料的研究进展,以及其在红外探测领域的应用情况,对其发展前景和趋势进行了展望。     

Cobalt-containing silicon oxycarbide glasses derived from poly[methyl(phenyl)]siloxane and cobalt phthalate

Cobalt-containing silicon oxycarbides have been produced by curing and pyrolysis of polymethyl(phenyl)siloxane resin Lukosil 901 and Co-phthalate blends. The structure of the Si(Co)OC glasses was studied by electron microscopy, back-scattered electron imaging (BSE), Raman and infrared spectroscopies. The cobalt incorporated into SiOC structure increases the polymerization degree of the glass phase. It seems that the free carbon phase is closing into the SiO(Co)C network. This idea also supports the results of combustibility studies – prepared glasses are characterized by excellent oxidation resistance at high temperatures.     

Methods of chemical and phase composition analysis of gallstones

This review presents the instrumental methods used for chemical and phase composition investigation of gallstones. A great body of data has been collected in the literature on the presence of elements and their concentrations, obtained by fluorescence microscopy, X-ray fluorescence spectroscopy, neutron activation analysis, proton (particle) induced X-ray emission, atomic absorption spectroscopy, high-resolution gamma-ray spectrometry, electron paramagnetic resonance. Structural methods—powder X-ray diffraction, infrared spectroscopy, Raman spectroscopy—provide information about organic and inorganic phases in gallstones. Stone morphology was studied at the macrolevel with optical microscopy. Results obtained by analytical scanning and transmission electron microscopy with X-ray energy dispersive spectrometry are discussed. The chemical composition and structure of gallstones determine the strategy of removing stone from the body and treatment of patients: surgery or dissolution in the body. Therefore one chapter of the review describes the potential of dissolution methods. Early diagnosis and appropriate treatment of the disease depend on the development of clinical methods for in vivo investigation, which gave grounds to present the main characteristics and potential of ultrasonography (ultrasound scanning), magnetic resonance imaging, and X-ray computed tomography.     

Structural study of sol-gel silicate glasses by IR and Raman spectroscopies

A study of the structure and bonding configuration of sol-gel silicate glasses by Raman and infrared spectroscopies is presented. Moreover, a review of the Raman lines and infrared bands assignment, the identification of the non-bridging silicon-oxygen groups and the ring structures are also demonstrated. The evolution of the changes of the bonding configuration in the composition and the stabilization temperature of the bioactive glasses is discussed in terms of the structural and textural characteristics of the glasses. Raman and infrared analyses contribute to the improvement in understanding of the local symmetry for sol-gel silicate glasses. infrared spectroscopy has allowed to identify the vibration bands of the hydroxyl groups associated with various configurations of the terminal silanol bonds on the glass surface and the free molecular water in the glass matrix. Raman analysis has provided an alternative method of quantifying the network connectivity grade and predicting the textural properties of the sol-gel silicate glasses.     

双迷宫型通道Helmholtz周期结构的低频带隙机理及隔声特性

为了解决飞机舱室中的低频噪声问题,本文设计了一种双迷宫型通道的Helmholtz周期结构。迷宫型开口通道的设计能够大大增加Helmholtz腔开口通道的长度,有效降低低频带隙下限,双通道的设计能够增加声子晶体局域共振的区域,可以增加低频带隙数目。本文采用有限元法(FEM)得到了该结构在0~500 Hz频率范围内的能带结构及隔声特性,经过深入研究发现,该Helmholtz 周期结构在0~500 Hz范围内存在多个低频带隙,且在低频范围内表现出较好的隔声特性。为了揭示其带隙产生机理,本文通过声-电类比方法建立了该结构的等效电路模型,并通过有限元法和等效电路模型,对低频带隙影响因素进行了详细分析。结果表明,增加开口通道的长度能够降低带隙起始频率,较小的晶格常数有利于拓宽带隙宽度。本文的研究进一步探索了声子晶体结构设计对带隙的影响,为解决飞机舱室的低频降噪问题提供了新方法。     

The electrical and optical properties of amorphous germanium-gallium alloys

The paper extends an earlier study of the far infrared properties of a series of evaporated amorphous GeGa alloys. The results of temperature dependent dc resistivity and near infrared and visible optical experiments are presented. Since the properties of amorphous films are dependent on the preparation conditions, a technique has been developed in which four samples of varying composition are prepared in the same evaporation. The far infrared data indicate that a significant fraction of Ga atoms dissolve in a-Ge with four-fold coordination. However, there is also indirect evidence of mixed valence.     

The infrared spectra of coordinated perchlorates

The infrared spectra of a series of copper(II) perchlorate complexes have been examined in the light of their known solid state structures and the spectroscopic predictions based on group theory. The spectra of complexes containing coordinated perchlorate are readily distinguished from those containing uncoordinated perchlorate by the presence of a second band near 650 cm^–1. The mode of coordination of the perchlorate ion to a complex cation, however, is difficult to determine on the basis of infrared spectroscopy alone.