温度对AZO薄膜红外辐射性能的影响

随着全球资源的减少和环境的恶化,节能减排已成为人们关注的焦点,具有保温隔热功能的低辐射玻璃成为研究的热点。提高玻璃保温隔热性能最有效的方法就是在其表面涂覆低辐射率层。原材料丰富、导电性能好、可见光透过率高等优势使得Al掺杂ZnO (AZO)薄膜成为最具潜力的低辐射率层。系统研究了温度对AZO薄膜红外辐射性能的影响,分析了变化机理。首先研究了在一定的温度下持续一段时间后,AZO薄膜的红外比辐射率的变化情况。然后研究了在变温环境中红外比辐射率的变化情况。采用直流磁控溅射法在室温下玻璃基片上沉积500 nm厚的AZO薄膜,将薄膜放到马弗炉中进行热处理,在100～400 ℃空气气氛下保温1 h,随炉冷却。采用X射线衍射仪对AZO薄膜进行物相分析,采用扫描电子显微镜观察薄膜表面形貌变化。利用四探针测试法测量AZO薄膜的电阻率,采用红外比辐射率测试仪测试薄膜红外比辐射率, 可见分光光度计测量可见光谱。测试的结果表明,薄膜热处理前后均为六角纤锌矿结构,(002)择优取向。300 ℃及以下热处理1 h后,(002)衍射峰增强,半高宽变窄,晶粒尺寸长大。随着热处理温度的升高,薄膜的电阻率先减小后增大,200 ℃热处理后的薄膜具有最小的电阻率(0.9×10-3 Ω·cm)。热处理温度升高,晶粒长大使得薄膜电阻率降低。热处理温度过高,薄膜会从空气中吸收氧,电阻率下降。薄膜的红外比辐射率变化趋势和电阻率的一致,在200 ℃热处理后获得最小值(0.48)。自由电子对红外光子有较强的反射作用,当电阻率低,自由电子浓度高的时候,更多的红外光子被反射,红外辐射作用弱,红外比辐射率小。薄膜的可见光透过率随着热处理温度的升高先减小后增大,200 ℃热处理后的薄膜的可见光透过率最小,但仍高达82%。这种变化是由于自由电子浓度变化引起的,自由电子对可见光有很强的反射作用。选取未热处理和200 ℃热处理后的样品进行变温红外比辐射率的测量,将样品放在可加热的样品台上,位置固定,在室温到350 ℃的升温和降温过程中每隔25 ℃测量一次红外比辐射率,结果表明,在室温到350 ℃的温度范围内,AZO薄膜的红外比辐射率在升温过程中随着温度的上升而增大,在降温过程中减小,经过整个升、降温过程后,薄膜的红外比辐射率增大。     

用于检测水环境中银离子浓度的荧光适体传感器研究

银凭借其独特的性能,在医疗材料、摄影、电子、成像等行业中应用广泛。然而,银离子被列为最具毒性的重金属离子之一,会对环境以及人类的生命健康造成严重威胁。为了灵敏、特异性的检测水环境中的银离子浓度,利用纳米金的优良光学猝灭性以及双链核酸适体捕获银离子能力更强的优点,结合荧光能量共振转移原理,提出一种用于检测水环境中银离子浓度的荧光适体传感器。将修饰SH键的核酸适体与纳米金混合形成稳定的纳米结构,并加入标记有FAM的核酸适体,形成检测银离子浓度的工作溶液。当不存在银离子时由于不匹配碱基C-C之间的排斥力导致两条核酸适体不结合,反应体系中具有较强的荧光;当存在银离子时,双链核酸适体中不匹配的C-C能与银离子通过金属离子-碱基的相互作用形成稳定的C-Ag+-C碱基对,这种复合结构的产生会拉近纳米金和荧光基团之间的距离,使得荧光信号随着银离子浓度的增加而逐渐减弱。根据加入银离子前后荧光强度的变化可实现银离子浓度的检测。同时,为了提高传感器的灵敏性和稳定性,实验优化了工作溶液中纳米金与核酸适体的浓度比、氯化钠浓度、缓冲液的pH以及培养温度等参数。结果表明,当浓度为0.012 5 g·L-1的纳米金与5 μmol·L-1核酸适体的体积比为5∶1,NaCl浓度为260 mmol·L-1,缓冲液pH 7,培养温度为30 ℃时,工作溶液初始荧光强度最强,银离子检出限为10 nmol·L-1,相关系数为R2=0.99。此外,该传感器对银离子的浓度检测表现出较好的特异性,且具有操作简单、灵敏和不引入有毒溶剂等优点,在水环境中的银离子浓度检测领域有较好的应用前景。     

纳米晶聚合物复合薄膜PbTiO3-PEK-c的电光特性及其弛豫过程的研究

制备了掺杂型纳米晶聚合物钛酸铅聚醚醚酮 (PbTiO3 PEK c)复合薄膜 ,采用简单透射技术测量了该复合薄膜的线性电光系数 ,并研究了该复合薄膜的电光特性的弛豫过程     

Ellipsometric analysis and optical absorption characterization of gallium phosphide nanoparticulate thin film

Gallium phosphide (GaP) nanoparticulate thin films were easily fabricated by colloidal suspension deposition via GaP nanoparticles dispersed in N,N-dimethylformamide. The microstructure of the film was performed by x-ray diffraction, high resolution transmission electron microscopy and field emission scanning electron microscopy. The film was further investigated by spectroscopic ellipsometry. After the model GaP+void|SiO₂ was built and an effective medium approximation was adopted, the values of the refractive index n and the extinction coefficient k were calculated for the energy range of 0.75 eV-4.0 eV using the dispersion formula in DeltaPsi2 software. The absorption coefficient of the film was calculated from its k and its energy gaps were further estimated according to the Tauc equation, which were further verified by its fluorescence spectrum measurement. The structure and optical absorption properties of the nanoparticulate films are promising for their potential applications in hybrid solar cells.     

超薄金壳包覆NaYF4:Yb,Er@SiO2纳米结构的可控合成与表面增强上转换荧光

利用原位还原法成功制备了尺寸均一、超薄完整金壳包覆的NaYF₄:Yb,Er@SiO₂@Au（NSA）纳米结构,其XRD、TEM、EDX、HRTEM-HAADF、Mapping及吸收光谱表征结果表明,SiO₂壳及纳米金壳的平均厚度分别约为5 nm和2 nm。在980 nm连续激光激发下,系统研究了核壳结构的上转换荧光强度与氯金酸浓度的依赖关系。稳态光谱结果显示,NSA与仅SiO₂包覆样品（NS）相比Er³⁺的红绿荧光强度均增强了~2.8倍。通过分析上转换荧光动力学过程及利用FDTD方法模拟,讨论了表面等离激元增强上转换荧光的机制。     

Laser‐Induced Self‐Assembled Nanostructures on Electron‐Transparent Substrates

Currently, one of the challenges in high‐resolution transmission electron microscopy (TEM) studies of nanomaterials is to make contamination‐free materials in a simple and time‐efficient way. Here, a method is demonstrated that combines nanosecond‐pulsed laser dewetting of thin films with a film float‐off technique to realize nanostructures (NSs) on electron‐transparent substrates in a robust and rapid manner. NSs of metal (Ag) and bimetals (AgCo, AuCo) ranging from 20 to 150 nm are synthesized on thin carbon film deposited on mica substrates. The NS/carbon system is subsequently transferred onto TEM grids by a float‐off process resulting from debonding of the carbon from mica due to their contrasting hydrophobic nature. This process enables the fabrication of different NSs on flexible and electron‐transparent substrates.     

Optical Thin-Film Sensors for the Determination of Aqueous Halide Ions

Fourteen thin-film optical sensors in which halide-sensitive fluorophores are immobilized in a thin copolymer film (50 m, dry) have been developed and characterized. The sensor films use rhodamine, 6-methoxyquinoline, and harmane dyes which have been functionalized and bound to a hydrophilic copolymer. The sensor films are reversibly capable of determining aqueous bromide and iodide with 4 and 2% accuracy, respectively, at concentrations of around 10^–3 mol dm^–3, and are more sensitive than previous plastic sensor fabrications. The 90% response time to molar iodide is 30–60 s. A combination of sensor films allows the simultaneous determination of both I^– and Br^– in a mixed-halide solution. The interference of several ions, including pseudo-halides, on the sensor films has been studied.     

磁场中液氦薄膜表面电子涟波子系统的性质

研究了磁场中液氦薄膜表面电子与涟波子强耦合和弱耦合的性质。采用线性组合算符方法导出磁场中液氦薄膜表面电子 涟波子系统的振动频率和基态能量。讨论磁场对表面电子 涟波子系统的振动频率和基态能量的影响。     

晶体偏光棱镜光强透射比研究

在菲涅耳公式、相位匹配条件和多光束干涉理论的基础上,将晶体偏光棱镜的各参量表示为合理的几何模型,得出了光强透射比随空间入射角的变化关系,并设计了验证光强透射比的实验,实验结果和理论推导相一致.结果表明：胶合层间的多光束干涉对棱镜光强透射比的影响不可忽略,对于空气隙型偏光棱镜,由于空气隙间多光束干涉的影响,光强透射比随任意角度变化较大,而用胶合介质胶合的棱镜,其透射比对空间入射角不是很敏感.     

Sb，In，P掺杂对SnO_2薄膜透明导电性能的影响(英文)

采用溶胶凝胶(Sol-Gel)技术制备了SnO2:(Sb,In)透明导电薄膜,优化了制备工艺参数,获得了最佳制备条件,研究表明,4%的铟掺杂有效地改善了薄膜的内部结构,使得紫外-可见光的透过率显著增加;7%的锑掺杂释放出了更多的载流子,使薄膜的方块电阻降低,2%的磷掺杂因准连续杂质能带的形成进一步提高了薄膜的电导率.Sb、In、P的掺入使得SnO2薄膜的紫外-可见光的透过率达83%,方块电阻达38Ω/□