染料掺杂的红色有机薄膜电致发光器件

近年来 ,有机发光二极管 (OL EDs)得到了广泛深入的研究[1～ 3] 。研究工作主要集中在探索新的有机荧光材料、载流子注入和输运材料 ,以及器件的新结构 ,力求得到发光效率高和稳定性好的各种不同颜色的发光。从目前的研究来看 ,尽管蓝色和绿色发光材料的效率已经足够高到实用 ,但红色发光材料仍然存在问题 ,对红色发光进行研究是非常必要的。有两条实现红色发光的途径 :掺杂能发红光的染料和用稀土离子配合物作基质或激活剂。利用能量传递的原理 ,在有机基质材料中掺杂荧光染料是获得高效、长寿命和所希望发光颜色的一种有效而简单的方法…     

ZnS中Er3+的正向注入电致发光

已报导的三价稀土离子(RE3+)和二价锰离子发光的电致发光器件,都是激发机理为碰撞激发的高场发光器件[1,2]。我们研究了znS:RE2+的带边激发光谱,由此提出了实现正向注入下三价稀土离子电致发光的发光器件的设想,这种器件的必要条件是在存在三价稀土离子的区域同时注入电子和空穴。在离子注入的ZnS:Er3+发光二极管上观察到了这种发光,实验证明不是碰撞激发,而是正向注入产生的发光。     

Ⅱ-Ⅵ族化合物薄膜电致发光

电致发光薄膜是平板显示器的重要材料之一,我们从研究ZnS:Mn,Cu直流电致发光薄膜的大面积稳定发光开始,首次将稀土离子引进直流电致发光薄膜,实现了各色的直流电致发光,并研究其激发机理、过热电子的能量分布、稀土离子的碰撞截面和稀土离子发光中心在晶格中的位置等。在国内首先研制成功ZnS:Mn交流电致发光薄膜计算机终端显示器,并扩大面积到640×480像素(对角线10英寸)。为了实现彩色化显示,研制出稀土离子掺杂的各色交流电致发光薄膜。研究不同稀土离子在薄膜中的浓度猝灭,以便提高薄膜的发光亮度。在致力于实现彩色的过程中,首要的任务是提高蓝色电致发光薄膜的亮度和探索新的蓝色电致发光薄膜材料:从ZnS:TmF₃到CaS:TmF₃,发光亮度有了很大的提高;使SrS:Ce薄膜蓝色电致发光的亮度超过1000cd/m²;同时探索纳米Si和非晶Si/SiO₂超晶格结构的蓝色电致发光。成功地实现了ZnS:Mn/SrS:Ce白色电致发光和SrS:HoF₃三基色线谱发射的白色电致发光,发光亮度也超过1000cd/m²。     

稀土离子的上转换发光及研究进展

稀土离子的上转换发光由于其在短波长激光器方面的潜在应用而受到了广泛的重视,本文总结了稀土离子中常见的几种不同的发光机制,分析了几种常见稀土离子在不同的泵浦方式下的发光方式,讨论了稀土离子上转换发光对基质成分的依赖性及其研究进展,并对稀土离子上转换发光的研究及应用进行了展望。     

Er3+/Yb3+/Tm3+共掺杂氟化物中红色上转换发光研究

氧化铒的质量增加到原来的10倍左右时发现两种配方的发光性质有明显不同。根据情况作研究了Er^3 ／Tm^3,Er^3 ／Er^3-和Er^3 ／Yb^3 /Tm^3 发光系统在980nm抽运下的荧光光谱和上转换发光的性质,以及在声子能量较低的氟化物中,3个发光系统建立的优先性和Er^3 离子浓度的关系。根据实验发现当Er^3 离子浓度由小逐渐变大时,绿光和红光的强弱比例也有明显的变化。其中作认为起决定性作用的是Er^3 离子浓度。因为在均匀体系中每个稀土离子的和另一个稀土离子的结合形成发光系统的机会是平等的,组成发光系统的稀土离子间的距离变化,即其中一种起决定作用的离子浓度变化时,那么它所组成的发光系统也就相应发生变化(稀土离子的优先结合性也会在此得到体现),从而发出的主色的光也就跟着变化。     

稀土离子的上转换发光及研究进展

稀土离子的上转换发光由于其在短波长激光器方面的潜在应用而受到了广泛的重视，本文总结了稀土离子中常见的几种不同的发光机制，分析了几种常见稀土离子在不同的泵浦方式下的发光方式，讨论了稀土离子上转换发光对基质成分的依赖性及其研究进展，并对稀土离子上转换发光的研究及应用进行了展望。     

彩色发光涂料的光学测量

彩色发光涂料是一种高光效、长余辉的光致发光材料。当对其进行光学测量时,为避免因激发光被探测器接收而对测量结果产生的影响,提出在实验中如何设定特殊的装置,从而保障对发光涂料的光学特性进行有效的测量。根据光度学理论中有关照度和发光亮度的关系,通过实验对三种不同的彩色发光涂料在同样光照条件下的亮度测量,同一种发光涂料在不同颜色光照下的发光亮度比较,以及在彩色发光涂料的亮度衰减情况给出了测量的结果。     

基于色域界定的多基色亮度均衡颜色转换算法

为实现多基色显示设备多通道亮度均衡程度最优的颜色转换,提出了一种基于凸包算法的多基色显示设备色域的界定方法,并提出了一种通过对亮度均衡程度评价函数进行非线性优化以求解出最优亮度均衡驱动值的颜色转换算法。在XYZ颜色空间均匀取样颜色坐标,通过凸包算法判断得到位于设备色域内的颜色坐标;计算出设备色域内颜色坐标对应的亮度均衡程度最优的多基色驱动值,从而建立XYZ颜色空间到多基色设备颜色空间的映射关系;以小间距点阵LED六基色显示器为实验平台,结合该显示器子像素的发光参数,实现了色域界定与亮度均衡颜色转换。结果表明提出的方法可实现平均亮度离散系数为0.1685的颜色转换。     

利用核壳结构实现纳米颗粒的多色上转换发光

将多色荧光标记技术应用于生物信息检测可实现快速、实时、同步大规模检测目标生物分子的目的,利用上转换纳米粒子作为多色荧光探针可有效地避免生物组织自荧光对检测信号的影响。本文制备了具有核-壳结构的稀土氟化物纳米粒子,并通过在核与壳不同位置共掺杂不同浓度的敏化离子和发光离子来改变发光离子各发射峰之间的相对强度。利用不同颜色和强度的发射光谱实现了纳米粒子的多色上转换发光。利用透射电子显微镜成像、X射线衍射分析、发光光谱等测量手段对多色上转换发光纳米粒子进行了形貌、结构和上转换发光性质的表征。实验结果表明,具有核-壳结构的纳米粒子尺寸小于30 nm,呈球形。在980 nm红外光激发下,纳米粒子呈现从红色到蓝紫色的颜色可变的上转换发光。     

生命科学研究中的稀土发光──稀土荧光探针及荧光标记在生物大分子研究中的应用

本文介绍了稀土发光在生命科学研究中的作用，从稀土发光基本知识入手，着重描述了稀土离子发光与生物大分子研究的关系，稀土离子作为荧光探针及荧光标记在生物大分子结构探测与分析方面的应用概况．     

磷锗锌光学参量振荡器技术研究

 报道了一台高重复频率2 mm光学参量振荡器泵浦的磷锗锌光学参量振荡器。磷锗锌晶体(ZnGeP₂，简称ZGP)采用Ⅰ类相位匹配方式，切割角度q为55°，f为0°，尺寸5.5 mm×6 mm×18 mm，在4.0 kHz重复频率下，当注入5.2 W的2 mm圆偏振光时，获得310 mW中红外输出，p偏振态2 mm到3～5 mm光-光转换效率12%。通过调节晶体的角度，实验获得ZGP光学参量振荡器的波长调谐曲线，在误差范围内与理论变化规律相符。     

A new method for the determination of the thickness and the refractive index of thin dielectric films evaporated on metal substrates

A new ellipsometrical method for the accurate determination of the thickness and the refractive index and hence the dispersion for thin transparent films evaporated on metal substrates is put forward. Results for zinc sulphide thin films evaporated in vacuum, 10⁻⁵ mm Hg, on antimony are reported.     

Luminescence of isoelectronic traps in laser-annealed,tellurium-coated zinc sulphide

The production of a single-tellurium and paired-tellurium isoelectronic trap luminescence centres in zinc sulphide by the Q-switched ruby laser irradiation of layers of thermally-deposited tellurium on the surface of zinc sulphide is described. Evidence is presented for surface melting of the zinc sulphide caused by the laser radiation. For the production of isoelectronic traps by the above-mentioned process the existence of an optimum energy of the laser radiation has been shown and its approximate value determined.     

On the discovery of an unusual luminescent pigment in Van Gogh’s painting “Les bretonnes et le pardon de pont Aven”

Spectrally and lifetime-resolved UV-induced luminescence imaging have been applied to the in situ analysis of Vincent Van Gogh’s painting on paper “Les bretonnes et le pardon de pont Aven”. The in situ investigation revealed the presence of an unusual microsecond green emission from the white painted areas of the watercolour, and this long-lived emission has not been reported in modern paintings by other authors. In order to attribute and suggest an identification of the luminescent pigment, our analysis was integrated with further measurements on commercially available modern white pigments (zinc white, Lithopone white, Blanc Fixe, zinc sulphide, and copper-doped zinc sulphide) and with an in-depth study of the synthesis processes of zinc-based pigments available at the end of the 19th century. Analysis suggested an attribution of the unusual emission from the Van Gogh painting to a particular variety of zinc sulphide pigment, characterized by the presence of copper impurities which were unintentionally introduced in the crystal matrix during its production. The present study is the first application of lifetime imaging for the mapping of long-lived luminescence from the semi-conductor pigment.     

铜管表面水合物晶体生长特性研究

实验研究了浓度分别为5 wt%、15 wt%、20 wt%、30 wt%的四丁基溴化铵(TBAB)溶液在外径为21mm的铜管外表面的结晶特性.实验首先以15 wt%TBAB溶液为例,观察其降温结晶过程,得到了TBAB水合物晶体在不同阶段生长的特征.然后对不同浓度、不同过冷度条件下的TBAB溶液进行降温结晶实验,观察并测...     

Cylindrical KTiOPO(4) crystal for enhanced angular tunability of phase-matched optical parametric oscillators

We demonstrate what is to our knowledge the first optical parametric oscillator (OPO) based on a cylindrical phase-matched nonlinear crystal. Experiments are performed with an uncoated KTiOPO(4) crystal cut as a cylinder with a diameter of 21.2 mm and a thickness of 5 mm. We achieve 20.5-internal-degree angular tuning in a 1064-nm-pumped type III OPO, which would correspond to ~36 degrees external angular rotation for a parallelepipedal crystal. The goals of using such a device are to narrow the spectral width of the output and to enhance the spatial quality of the generated beams in widely tunable OPO's.     

Microstructure and properties of plastic deformed martensite induced by laser shock processing

Firstly, 45# steel was quenched by the NEL-2500A rapidly axial flow CO2 laser. The experimental parameters were the laser power of 750 W, the laser beam diameter of 4 mm, the scanning velocity of 7 mm/s.The thickness of coating layer was 0.1 mm and the width was 8 mm. Secondly, the martensite induced by laser quench was shocked by Nd:YAG laser. The parameters of laser shock processing were the wavelength of 1.06 μm, the pulse duration of 23 ns, and the output energy of 16-20 J. The laser was focused on a spot of φ7 mm. K9 optical glass was used as confinement. The sample was coated with black paint 86-1 (the thickness is about 0.025 mm). By testing and analysis of samples which were treated by laser quench and laser quench+shock with transmission electron microscope (TEM), it was discovered that the surface layer of martensite was deformed plastically by laser shock processing. In the secondary hardened zones,there were a lot of slender secondary twin crystal martensites, dislocation tangles, and cellular dislocations.Compared with that of the hardened zones through laser quench only, the residual stress and mechanical properties of the secondary hardened zones were improved and increased through laser compound method.     

Surface layer structure degradation of rails in prolonged operation

By methods of optical, scanning and transmission electron microscopy and microhardness measurement the transformation regularities of structure-phase states, defect substructure, fracture surface and mechanical properties of rail surface layer up to 10 mm deep in process of long-term operation (passed tonnage of gross weight 1000 mln. tons) were revealed. According to the character of fracture and level of structure imperfection the three layers were detected: surface, transition and boundary ones. It has been shown that the surface layer ~20 μm in thickness has a multiphase, submicro- and nanocrystalline structure and it contains micropores and microcracks. The increased density of bend extinction contours at 2 mm depth from the tread contact surface was noted, and it was shown that the maximum amplitude of stress fields was formed on the interphase boundary the globular cementite particle–matrix. The evaluation of stress fields was done.     

超薄LiTaO3晶片的键合减薄技术

在制造红外热释电探测器阵列过程中，需要利用超薄钽酸锂(LiTaO₃)晶片作为红外热释电探测器件的敏感层。通常LiTaO₃晶片的厚度远厚于红外热释电探测器件要求的厚度，所以需要采用键合减薄技术对LiTaO₃晶片进行加工处理。键合减薄技术主要包括：苯并环丁烯（BCB）键合、铣磨、抛光、加热剥离、刻蚀BCB。加工后得到面积为10mm×10mm、厚度为25μm的超薄单晶LiTaO₃薄膜，晶片厚度、表面粗糙度和面形精度比较理想。测得了LT晶片减薄后的热释电系数为1.6×10^-4Cm^-2K^-1。得到的单晶LiTaO₃薄膜满足红外热释电探测器敏感层的要求。     

ZnSe MIS二极管蓝色电致发光的空间分布

本文研究了用ZnS多晶薄膜作绝缘层时制备的ZnSe MIS二极管,在正向电压激发下的蓝色电致发光的空间分布,在光学显微镜下观察到电致发光呈稀疏的点状分布。为了了解发光点的起因,用扫描电镜观测了二极管的二次电子像(SEI),束感生电流像(EBICI)和吸收电流像(AEI)。一个重要的发现是二极管的电致发光点(ELS)和EBICI有相当好的对应关系。文中指出了发光点的存在与绝缘层(Ⅰ)的引入有关。绝缘层一半导体(I-S)界面较大的能带失配和较差的结合,从而产生较多的无辐射复合中心,是产生稀疏发光点可能的原因。文中根据对发光点起因的分析,提出用ZnSe多晶薄膜取代ZnS多晶薄膜作绝缘层来铡备ZnSe MIS二极管。当用显微镜观察时,电致发光点呈密集分布,而用肉眼观察时是均匀的蓝色发光。文中还指出了进一步改进电致发光空间分布的可能途径。