紫外增强Lumogen薄膜旋涂法制备及其性能表征

Lumogen薄膜用于固态硅基探测器件CCD紫外增强具有显著的成本和工艺优势。研究旋涂法制备Lumogen薄膜的CCD紫外增强技术,通过对薄膜的光谱分析得到优化的制备工艺。制备的薄膜在可见光波段透过率较高,对紫外波段的光具有较强的吸收,其发射峰位于525 nm,并且激发谱较宽, 涵盖200～400 nm。实验结果表明使用旋涂法制备的紫外增强薄膜,能将紫外光转化为可见光,并且在增强紫外响应的同时,不削弱可见波段的响应,是一种有效增强固态检测器紫外响应的紫外增强薄膜。     

紫外增强薄膜发射光谱测量中的倍波现象分析

紫外探测技术足继激光和红外探测技术之后发展起来的又一军民两用光电探测技术,在普通探测器件光敏面镀上将紫外波段的光转化为可见波段的光的变频薄膜是增强光电探测器紫外响应的主要技术.文章用"旋涂法"制备成像器件紫外增强薄膜.在对紫外增强薄膜的量子转化效率进行测量分析的实验过程中用SP1702紫外可见光栅光谱仪对薄膜的紫外变频效率进行分析,在激发光源为260和280nm时变频薄膜的发射光谱在520和560 nm附近有较明显的波峰.结合光栅光谱仪的工作原理,对该现象进行了理论分析,得出520和560 nm附近的波峰并非变频薄膜受激发发出的光波,而是光谱测量中产生的倍波现象.从分离重级光谱的角度没计了光谱分级器,以消除光谱测鼍中倍波现象的影响.     

高响应度倍增型碳纳米管-有机红光探测器

采用溶液旋涂方法将单壁碳纳米管与有机红光材料结合并制作出红光探测器,研究了单壁碳纳米管对PBDTTT-F∶PCBM本体异质结活性层薄膜的影响机理及其红光探测器的光电特性.利用原子力显微镜,荧光光谱和紫外-可见吸收光谱等方法对器件进行性能表征及优化.当单壁碳纳米管为最优掺入比1.5wt%时,在-1V偏置电压时,红光光照下该探测器响应度为535mA/W,比探测率达到3.8×1012 Jones,外量子效率达到104%.结果表明,将单壁碳纳米管与有机红光材料结合,有利于提高有机共轭聚合物的聚集以及结晶度,增强光吸收,可为活性层提供高迁移率的电荷传导通道,优化薄膜互穿网络形貌.同时,利用碳纳米管的多激子产生效应,使得有机光电探测器的光电性能大大改善,外量子效率超过100%,为无机-有机光电探测器的进一步开发提供参考.     

旋涂法和热蒸发制备紫外CCD用晕苯薄膜的性能对比

晕苯是一种用于真空紫外光致发光重要的下转换材料。本文研究旋涂法和热蒸发法制备紫外CCD用晕苯薄膜的工艺方法,并对所制备的两种薄膜的性能进行了表征和对比。测试结果表明：旋涂方式成膜工艺简单,材料利用率较高,并且保持了荧光材料本身固有的晶体结构,但是膜面粗糙度较大;热蒸发方式成膜后紫外吸收较强,荧光发射强度相对较高,成膜后膜面粗糙度较小;热蒸发工艺在加热过程中改变了晕苯的晶体结构并形成了新的结晶态;相比于旋涂法,热蒸发的整个制备工艺相对复杂,并且生产成本较高。此外,该对比性研究工作为实现不同要求(如荧光发射强度、表面粗糙度、生产成本等)的荧光下转换薄膜的制备提供了理论指导。     

固溶体半导体ZnS1-xTex(0≤x≤1)多晶薄膜的制备及特性研究

ZnS1-xTex是制作短波长光波段光电子器件和紫外探测器的理想材料。本文介绍了ZnS1-xTex多晶薄膜的真空蒸镀制备情况，并用原子力显微镜、X射线衍射仪、能量色散谱仪、紫外．可见分光光度计、荧光光谱分析仪等对制备的多晶薄膜的性质进行了测试和分析，发现该多晶薄膜保持了单晶薄膜的紫外吸收、光致发光等良好特性。     

旋涂法快速制备双层二元胶体微球有序薄膜

以较大粒径的聚苯乙烯或SiO₂胶体微球的单层有序薄膜作基膜,较小粒径的SiO₂微球作第二层,用分步旋涂法快速制备了二元双层胶体微球复合有序薄膜.膜中小粒径微球与大粒径微球的粒径比γ=020—056,大粒径与小粒径微球的排列方式可表示为LS_x（x=1,2,…,13）.旋涂速度、旋涂时间、微球悬浮介质的黏度、悬浮液中微球的数密度、旋涂衬底的可润湿性等因素均会影响旋涂组装胶粒薄膜的质量.在旋涂衬底能够被胶体微球悬浮介质完全润湿的前提下,适宜的胶体微球数密度、旋涂速度、旋涂时间是旋涂组装有序薄膜的必要条件. 关键词： 复合有序薄膜 分步旋涂 胶体微球模板     

氧化镓薄膜的制备及其日盲紫外探测性能研究

采用射频磁控溅射方法在蓝宝石单晶衬底上沉积氧化镓(Ga2O3)薄膜,并通过光刻剥离工艺(Lift-off)制备了金属-半导体-金属结构的Ga2O3日盲紫外探测器。对不同温度下沉积的Ga2O3薄膜分析表明,在800℃下获得的薄膜结晶质量最好,薄膜的导电性则随着沉积温度的上升先增大后减小。在800℃制备的β-Ga2O3薄膜的可见光透光率大于90%,光学吸收边在255 nm附近。在10 V偏压下,探测器的暗电流约为1n A,光电流达800 n A,对紫外光响应迅速。器件的响应度达到0.3 A/W,260 nm波长处的响应度是290 nm波长对应响应度的40倍,可实现日盲紫外波段的探测。     

MgF_2薄膜对荧光薄膜紫外响应灵敏度的增强特性研究

在光敏面上镀制荧光薄膜将紫外光转变为可见光,是提高CCD和CMOS图像传感器紫外响应灵敏度的一种有效方法。针对荧光薄膜入射界面的散射和反射损耗降低荧光发光强度的分析,研究在荧光薄膜上镀制增透膜和阻隔膜的灵敏度增强特性。采用真空热阻蒸发的镀膜方法分别制备了单层Lumogen荧光薄膜和MgF2/Lumogen复合膜。利用原子力显微镜,紫外可见近红外分光光度计,荧光光谱仪对两种样品的表面粗糙度,漫反射和透射光谱以及荧光发光光谱分别进行对比测试分析。结果表明:MgF2保护层降低了表面粗糙度,减小了入射界面的漫反射损耗,对500~700nm的可见波段具有明显增透作用,也增强了Lumogen薄膜对紫外波段受激发射的荧光强度;同时,MgF2薄膜的抗损伤及水汽隔离性能对荧光薄膜紫外响应能力具有保护作用,为延长紫外CCD薄膜及器件的工作寿命提供了有效手段。     

利用双给体实现可见光范围高探测率 有机光电探测器

采用P3HT∶PBDT-TT-C∶PC_(61)BM为活性层,通过溶液旋涂和高真空蒸镀工艺制备了覆盖可见光范围的高探测率有机光电探测器.利用原子力显微镜、紫外可见吸收光谱和荧光光谱研究了窄带隙聚合物红光吸收材料PBDT-TT-C掺入P3HT∶PC_(61)BM对活性层薄膜光学特性和器件电学特性的影响.研究发现当活性层中P3HT∶PBDT-TT-C∶PC_(61)BM质量比为8∶2∶10时,活性层的响应光谱范围拓宽到350～780 nm.其探测器在-1 V偏压下红绿蓝三基色的光响应度和外量子效率分别达到了422 mA/W、464 mA/W、286 mA/W和83%、108%、77%,比探测率均达到10~(12)Jones以上.结果表明,在有机光电探测器活性层中掺入吸收光谱互补的有机材料,在保证薄膜微观形貌的基础上,通过调节三元混合材料的质量比,不仅可以优化载流子的产生和输运,提高器件的光电流,还可通过第三组分的掺入促进薄膜结晶,减小器件的暗电流.     

利用晕苯增强CCD紫外响应的实验研究

传统的电荷耦合器件(CCD),在400nm以下CCD的量子效率太低,而传统的基于CCD的紫外增强技术可以提高CCD对紫外波段的响应,但是存在光谱信号弱的缺点,并且系统分辨率也因此降低。一种自行研制的CCD紫外荧光增强技术,其创新在于去除CCD表面保护玻璃,通过真空镀膜的方法将晕苯直接沉积在CCD敏感元件表面,能有效地提高CCD的紫外响应度,并削弱薄膜对分辨率的影响。对于离散谱线,253.6nm波长的相对强度提高10倍。对于连续谱线,紫外波段的信号也得到明显增强,截止频率从290nm降至220nm。该种方法制作紫外CCD成本不高,可以实现批量生产,适合工业应用。     

Effect of substrate curvature on thickness distribution of polydimethylsiloxane thin film in spin coating process

The polymer spin coating is critical in flexible electronic manufaction and micro-electro-mechanical system(MEMS)devices due to its simple operation, and uniformly coated layers. Some researchers focus on the effects of spin coating parameters such as wafer rotating speed, the viscosity of the coating liquid and solvent evaporation on final film thickness.In this work, the influence of substrate curvature on film thickness distribution is considered. A new parameter which represents the edge bead effect ratio(re) is proposed to investigate the influence factor of edge bead effect. Several operation parameters including the curvature of the substrate and the wafer-spin speed are taken into account to study the effects on the film thickness uniformity and edge-bead ratio. The morphologies and film thickness values of the spin-coated PDMS films under various substrate curvatures and coating speeds are measured with laser confocal microscopy. According to the results, both the convex and concave substrate will help to reduce the edge-bead effect significantly and thin film with better surface morphology can be obtained at high spin speed. Additionally, the relationship between the edge-bead ratio and the thin film thickness is like parabolic curve instead of linear dependence. This work may contribute to the mass production of flexible electronic devices.     

样品厚度对薄膜法X射线荧光光谱测量的影响研究

分别以富集有Cr,Pb和Cd三种元素的尼龙薄膜样品及玻璃纤维滤膜为研究对象,采用滤膜叠加的方式,通过XRF光谱仪测量不同样品厚度下薄膜样品的XRF光谱,根据测得的尼龙薄膜样品中Cr,Pb,Cd元素及玻璃纤维滤膜中Ca,As和Sr元素特征XRF性质的变化,研究样品厚度对薄膜法XRF光谱测量的影响。结果表明：薄膜样品厚度对不同能量区间上元素特征谱线荧光性质的影响并不相同。元素特征谱线能量越大,元素特征X射线荧光穿透滤膜到达探测器的过程中损失越少;但由薄膜样品厚度增加引起的基体效应却越强,相应特征谱线位置处的背景荧光强度就越大,因此样品厚度增加所引起的基体效应对薄膜法XRF光谱测量的灵敏度影响就越大。对于特征谱线能量较低(能量小于7 keV)的元素,以增加薄膜样品厚度的方式来增加待测组分的质量厚度浓度,并不能有效地提高薄膜法XRF光谱测量的灵敏度;对于特征谱线能量较高的元素(能量＞7 keV),可以通过适当增加样品厚度以增加被测组分的质量厚度浓度的方式来提高XRF光谱测量的灵敏度,薄膜样品厚度在0.96～2.24 mm内,更有利于XRF光谱的测量与分析。该研究为大气及水体重金属薄膜法XRF光谱分析中薄样制备及富集技术提供了重要的理论依据。     

Molecular crystallization of rubrene thin films assisted by gold nanoparticles

We demonstrate that crystalline organic rubrene thin films can be obtained by a facile spin-coating method using gold (Au) nanoparticles (NPs). Dodecanethiol-functionalized Au NPs were dissolved with rubrene molecules in solvent and a thin film of Au/rubrene was prepared by a simple spin coating process. The results of confocal photoluminescence (PL) and absorption spectral mapping confirmed the local formation of orthorhombic crystalline structures of the Au/rubrene hybrid film, in contrast to the monoclinic structure of plain rubrene films. Further, the results of transmission electron microscopy (TEM) and X-ray diffraction analysis, as well as Raman spectroscopy measurements of the rubrene and Au/rubrene films suggested the formation of high crystalline Au/rubrene film. The molecular crystallization of the Au/rubrene hybrid film is attributed to the nucleation effect of the Au NPs.     

Tailoring of the spectral–directional characteristics of rare-earth fluorescence by metal–dielectric planar structures

It is demonstrated that the spectrum, direction and polarization of rare-earth fluorescence can be tailored by embedding the impurity ions into a planar metal–dielectric structure (MDS). The latter was designed by spin coating a rare-earth-doped oxide film (TiO₂:Sm³⁺) onto a gold-covered glass substrate. For spectral–directional investigations of Sm³⁺ fluorescence, the MDS was attached to a semi-cylindrical prism and excited by UV light from the flat side. An angular scan revealed a strongly polarized and directional emission of Sm³⁺ from the convex side of the prism. The tuning of TiO₂ film thickness in the MDS allows a control of the polarization and direction of the emission bands. A theoretical modeling of the reflectivity of the MDS suggests that the observed angular resonances in the fluorescence emission are caused by its effective coupling with surface plasmons on the gold–dielectric interface or coupling with leaky modes in sufficiently thick dielectric films working as a waveguides.     

A study of the fluorescent properties of spin-coated sodium salicylate thin films

Thin films of sodium salicylate were deposited by spin coating from a solution prepared by dissolving sodium salicylate in methanol. The films were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, UV-visible spectroscopy and spectrofluorometry. The films were crystalline with a strong blue fluorescence peak at an emission wavelength of 419.3 nm. The influence of solution concentration, spin speed and annealing temperature on the fluorescence intensity was studied. Optimum results were obtained with a solution whose concentration was 2.5 M. It was found that lower spin speed resulted in higher fluorescence intensity. Moreover, the fluorescence intensity decreased as the annealing temperature was increased. The durability of the films over a period of 30 days was also investigated, and films annealed at higher temperatures were found to be less degraded with time.     

X-ray photoelectron spectroscopy characterization of composite TiO2–poly(vinylidenefluoride) films synthesised for applications in pesticide photocatalytic degradation

X-ray photoelectron spectroscopy (XPS) was adopted for the analytical characterization of composite titanium dioxide–poly(vinylidenefluoride) (TiO₂–PVDF) films developed for applications in the photocatalytic degradation of pollutants.

The composites were deposited on glass substrates by casting or spin coating from TiO₂–PVDF suspensions in dimethylformamide (DMF). XPS data on the TiO₂–PVDF surface composition were used to optimize preparation conditions (composition of the TiO₂/PVDF suspension, deposition technique) in terms of titanium dioxide surface amount and film stability.

The use of spin-coating deposition and the increase of TiO₂ amount in the DMF suspensions were found to improve the titanium surface content, although high TiO₂/PVDF ratios led to film instability. PVDF–TiO₂ films were also used in preliminary photocatalytic degradation tests on isoproturon, a phenylurea herbicide, under solar UV irradiation; the results were compared to direct photolysis to evaluate the catalytic efficiency of immobilized TiO₂ and the role played by the PVDF film during the degradation process.     

有机和无机国画颜料漫反射光谱和吸收光谱特征研究

国画颜料解混一直是古画颜料研究的重要内容,其中光纤反射光谱（FORS）是无损化探测颜料类别的常用手段。通过CCD光纤光谱系统,从光谱线型对国画颜料进行了分类,分别探测了两种有机植物颜料藤黄和胭脂在不同比例混合下的漫反射光谱与吸收光谱,并获取了不同色系无机矿物质颜料混合后的漫反射光谱。分析了单一颜料和混合颜料的光谱特征峰值,运用多元线性回归（MLR）以及一阶导数光谱法（FDS）,通过全波段线性解混获得了各组分颜料的比例。经过实验与理论分析,藤黄与胭脂的漫反射光谱为S型,混合颜料一阶导数光谱中两特征峰的位置分别为536和649 nm,在漫反射光谱中多元线性回归基本适用于该混合颜料的解混并显示出一定的线性规律,但无法精确地解混。而混合颜料的吸收光谱与单色光谱之间存在较好的线性关系,解混误差在5%左右。无机矿物质颜料中的漫反射光谱有S型（石黄和赭石）和钟型（石青和石绿）两种。首先,对于S型（石黄）与S型（赭石）混合颜料漫反射光谱,赭石的一阶导数光谱出现明显的“三峰”现象,并且混合颜料一阶导数光谱在534 nm处出现新的特征峰。多元线性回归理论虽适用于该混合颜料的解混,但由于不同颜料解混的权重因子不同,无法形成较为精准的线性模型。其次,对于S型（赭石）与钟型（石绿）混合颜料的反射光谱需要多元线性回归与导数光谱法共同判断混合比例的基本趋势,该光谱在400～800 nm范围内仅有一个交叉点。最后,利用钟型（石青）与钟型（石绿）混合颜料反射光谱的特征峰位置,即可判断出颜料混合比例的特征,随着混合比例的变化,反射光谱特征峰在457～524 nm出现了明显的横向移动,并且混合颜料光谱的峰值强度有明显的减弱。     

P3HT:PCBM薄膜成膜过程对聚合物太阳能电池性能的影响

P3HT:PCBM薄膜的快速和缓慢成膜过程能显著的改变异质结聚合物太阳能电池性能.通过调节旋转时间以及薄膜退火前的间隔时间,研究了P3HT:PCBM混合薄膜缓慢生长所需最佳时间.结果表明,在转速800 r·min-1下旋涂薄膜,经过50～80 s的旋涂,接着放置样品薄膜30 min以上,然后再对薄膜进行退火处理,电池效...