可逆热透明成像材料记录层的制备及形态与性能的研究

以纤维素为基体树脂,硬脂酸、聚乙二醇硬脂酸酯等为添加物,制备了1种可逆热透明成像材料的热敏记录层。利用差示扫描量热仪、偏光显微镜等研究了记录层材料热变化中的形态与性能。研究表明,该记录层具有良好的热光性质,硬脂酸和聚乙二醇硬脂酸酯的协同作用使得记录层的光学和热学性质有了进一步的提高。     

BSTS透明微晶玻璃及其三阶非线性光学性能

以SrO-BaO-TiO2-SiO2(简称BSTS)为基础玻璃系统,通过热处理工艺研究,制备出了以极性晶体Ba2-xSrXTiSiO8为主晶相的透明微晶玻璃,利用光学克尔系统测定了微晶玻璃的三阶非线性光学系数,实验表明,微晶玻璃的三阶非线性效应源于电子响应,基本没有振动转动等其它弛豫过程.     

Nd:YAG透明陶瓷制备技术的研究进展

掺钕钇铝石榴石(Nd：YAG)透明陶瓷是新一代固体激光材料。同Nd：YAG单晶和钕玻璃相比，Nd：YAG透明陶瓷及其制备技术具有许多优点，例如可获得掺杂浓度更高、尺寸更大的材料，可实现多层、多功能陶瓷复合结构，同时成本较单晶生长低，可实现大规模生产等，因而受到广泛重视。文中对近年来Nd：YAG透明陶瓷激光材料的研究进展、制备技术及其激光器的发展进行了综合评述，并展望了其应用前景。     

Er3+,Er3+-Yb3+和Er3+-Na+掺杂CaF2透明陶瓷的光学性能

以Ca(NO3)2、Er(NO3)3、Yb(NO3)3、KF和NaF为原料,采用热压烧结方法制备出Er3+,Er3+-Yb3+和Er3+-Na+掺杂CaF2透明陶瓷。测试了样品室温吸收光谱和发射光谱。利用Judd-Ofelt理论分析了样品的光学性能,并对吸收光谱进行计算拟合,得到光谱参数?t (t=2,4,6),根据光谱参数?t计算出Er3+某些能级的的跃迁几率、荧光分支比、辐射寿命和品质因子,讨论并比较了Er3+-Yb3+和Er3+-Na+共掺对CaF2透明陶瓷光学性能的影响。结果表明：掺杂Yb3+和Na+改变了Er3+光谱参数;Er3+-Yb3+共掺有利于提高样品的荧光强度;Er3+-Na+共掺有利于提高荧光寿命。     

层层自组装制备透明超疏水表面

利用层层自组装技术在玻璃表面上沉积二氧化硅纳米颗粒与聚苯乙烯球,高温烧结去除苯乙烯球后可在玻璃基底上构筑由二氧化硅纳米颗粒组成的阶层纳米粗糙微观结构,然后利用1H,1H,2H,2H-全氟癸基三乙氧基硅烷(FAS)进行表面疏水化处理制备透明超疏水表面,该表面与水的接触角高达166°。实验考察SiO2颗粒粒径对超疏水表面性能的影响并针对超疏水表面进行了扫描电镜、傅立叶变换红外光谱、接触角及热重表征。     

Transparent conductive oxide films mixed with gallium oxide nanoparticle/single-walled carbon nanotube layer for deep ultraviolet light-emitting diodes

We propose a transparent conductive oxide electrode scheme of gallium oxide nanoparticle mixed with a single-walled carbon nanotube (Ga₂O₃ NP/SWNT) layer for deep ultraviolet light-emitting diodes using spin and dipping methods. We investigated the electrical, optical and morphological properties of the Ga₂O₃ NP/SWNT layers by increasing the thickness of SWNTs via multiple dipping processes. Compared with the undoped Ga₂O₃ films (current level 9.9 × 10^-9 A @ 1 V, transmittance 68% @ 280 nm), the current level flowing in the Ga₂O₃ NP/SWNT increased by approximately 4 × 10⁵ times and the transmittance improved by 9% after 15 times dip-coating (current level 4 × 10^-4 A at 1 V; transmittance 77.0% at 280 nm). These improvements result from both native high transparency of Ga₂O₃ NPs and high conductivity and effective current spreading of SWNTs.     

The co-optimization of efficiency and emission bandwidth in GSAGG:Cr3+ NIR ceramic phosphors

The NIR phosphor-converted light-emitting diode (NIR pc-LED) is a new near-infrared light source that has been widely studied. Among various NIR phosphors, Cr³⁺ doped gadolinium aluminum gallium garnet (GAGG:Cr³⁺) ceramic phosphor has shown great potential due to its ultra-high efficiency and thermal stability. Despite its capabilities, its detection range may be limited due to a relatively narrow emission bandwidth. To make the GAGG:Cr³⁺ ceramic phosphors achieve both high efficiency and broadband emission, a series of Gd₃Al_2-x-ySc_xGa₃O₁₂:yCr³⁺ (GASGG:Cr³⁺) ceramic phosphors were prepared. Thanks to the decrease of crystal field strength with the doping of Sc³⁺, the full width at half maximum (FWHM) of GASGG:Cr³⁺ ceramic phosphors were extended from 84 nm to 117 nm, and the emission peak exhibited a red-shift of 46 nm. Meanwhile, it still retained extremely high external quantum efficiency (EQE = 47%) and excellent thermal stability (90.7%@150 °C). Then, a NIR pc-LED prototype device was fabricated by combining GASGG:Cr³⁺ ceramic phosphor with a blue LED chip. The NIR light output power and the photoelectric conversion efficiency of this device achieved 646 mW and 19.2%, respectively. Finally, the application effect in night vision and venography of this prototype device was demonstrated.     

Study on robust additive of CaCO3 for fast fabrication of highly transparent AlON ceramics by pressureless sintering

Fabrication of transparent AlON ceramics is extra sensitive to both particle size of starting powder and sintering additive due to shuttling transformation between AlON and Al₂O₃ + AlN during heating. One possible solution is to select robust additive to suppress the shuttling transformation. In this work, three AlON powders with different median particle sizes of 0.6, 0.9, and 1.1 μm were prepared. After studying the effect of CaCO₃ on densification process, AlON ceramics with the maximum transmittance of ≥81.1% were successfully fast prepared by pressureless sintering (PS) at 1880°C for only 2.5 h by using three AlON powders doped with different CaCO₃ amount. Specifically, AlON ceramics prepared from 1.1 μm with 0.5–0.8 wt.% CaCO₃ doping consistently showed the maximum transmittance of ≥85.3%, which indicates that CaCO₃ can serve as a robust additive to enable fast fabrication of highly transparent AlON ceramics even by PS.     

镁铝尖晶石透明陶瓷的研究进展

高性能透明陶瓷既具有陶瓷材料的耐高温、耐腐蚀、高绝缘、高强度等特性,又具有玻璃材料的光学性能,是极端环境用的重要光学材料。镁铝尖晶石作为透明陶瓷材料的一种,具有立方各向同性、低密度、高熔点、高硬度、高电阻、低热膨胀、高抗热震、耐腐蚀、高强度、近紫外到中红外的透光性和高温稳定性等优异性能,在国防军事、航空航天、激光照明、医疗器械等众多领域备受青睐;而且已广泛应用于红外制导窗口、高马赫航空器的整流罩、透明装甲和极端环境下的光电设备等关系国防安全与核心竞争力的关键领域。镁铝尖晶石透明陶瓷的研究起步很早,在多年的研究中,科研工作者不断改进镁铝尖晶石粉体合成工艺和烧结技术,形成了逐渐完善的镁铝尖晶石透明陶瓷制备体系,已经在强度、纯度、致密度和透光性等方面大有突破。然而,由于镁铝尖晶石透明陶瓷是多晶陶瓷,光散射位点多,影响因素多,使得高性能镁铝尖晶石的制备仍然具有一定难度。因此,本文将系统综述镁铝尖晶石的原料合成、烧结工艺及其对镁铝尖晶石透明陶瓷结构和性能的影响,旨在阐明镁铝尖晶石的原料-工艺-结构-性能关系以及存在的主要问题与解决方案,为制备极端环境用高性能镁铝尖晶石透明陶瓷提供参考。     

Preparation of transparent Bi2O3-ZnO-B2O3 glass by conventional sintering at low temperatures

Glass components fabricated by the sintering route have wide-ranging applications. However, one issue is that the crystallization tendency of glass powders often leads to residual pore-glass interfaces and crystal-glass interfaces, thereby causing strong light scattering and rendering the sintered glass opaque. This issue is particularly pronounced in glasses with a low glass transition temperature (T_g) due to their weak bonding and thus high crystallization tendency. In the present study, a Bi₂O₃-ZnO-B₂O₃ glass with a low T_g of 364°C was fabricated using the conventional sintering method to explore whether transparent glass materials can be obtained. The temperature range of crystallization of the glass powders was analyzed using differential scanning calorimetry. X-ray diffraction was employed to analyze the crystalline phases formed in the sintered glasses. The microstructure of the sintered glasses was examined using scanning electron microscopy. The optical transmittance of the sintered glasses was measured using ultraviolet-visible spectroscopy. The results show that transparent sintered glasses with the highest transmittance of 54% at the wavelength of 650 nm can be obtained by using a coarser initial particle size, lower forming pressure, and an appropriate sintering temperature/time (430°C/30 min). It is suggested that this combination of processing parameters can suppress glass crystallization while maintaining a low glass viscosity during sintering.