截止吸收型颜色玻璃的着色技术

研究了着色剂加入量对玻璃着色的影响和着色剂配比、热处理条件等对玻璃光截止吸收性能的影响。结果表明,着色剂Se加入的质量分数为0 6%左右,着色剂CdS加入的质量分数为0 6%～1 0%时,能制备出着色均匀的颜色玻璃;玻璃的光截止吸收性能主要取决于Se与CdS质量比和热处理条件;采用光谱纯着色剂可以明显提高玻璃的光透过效率。     

Substrate Evolution to Microstructural and Optoelectrical Properties of Evaporated CdS Thin Films Correlated with Elemental Composition

A typical high-e fficiency solar cell device needs the best lattice matching between different constituent layers to mitigate the open-circuit voltage loss. In the present work, the physical properties of CdS thin films are investigated where films with 100 nm thickness were fabricated on the different types of substrates viz. soda–lime glass, indium-doped tin oxide(ITO)-and fl uorine-doped tin oxide(FTO)-coated glass substrates, and silicon wafer using electron beam evaporation. The X-ray diffraction patterns confirmed that deposited thin films showed cubic phase and had(111) as predominant orientation where the structural parameters were observed to be varied with nature of substrates. The ohmic behaviour of the CdS films was disclosed by current–voltage characteristics, whereas the scanning electron microscopy micrograph revealed the uniform deposition of the CdS films with the presence of round-shaped grains. The elemental analysis confirmed the CdS films deposition where the Cd/S weight percentage ratio was changed with nature of substrates. The direct energy band gap was observed in the 1.63–2.50 eV range for the films grown on different substrates. The investigated properties of thin CdS layers demonstrated that the selection of substrate(in terms of nature) during device fabrication plays a crucial role.     

Facile Synthesis of Monodisperse CdS Nanocrystals via Microreaction

CdS-based nanocrystals (NCs) have attracted extensive interest due to their potential application as key luminescent materials for blue and white LEDs. In this research, the continuous synthesis of monodisperse CdS NCs was demonstrated utilizing a capillary microreactor. The enhanced heat and mass transfer in the microreactor was useful to reduce the reaction temperature and residence time to synthesize monodisperse CdS NCs. The superior stability of the microreactor and its continuous operation allowed the investigation of synthesis parameters with high efficiency. Reaction temperature was found to be a key parameter for balancing the reactivity of CdS precursors, while residence time was shown to be an important factor that governs the size and size distribution of the CdS NCs. Furthermore, variation of OA concentration was demonstrated to be a facile tuning mechanism for controlling the size of the CdS NCs. The variation of the volume percentage of OA from 10.5 to 51.2% and the variation of the residence time from 17 to 136 s facilitated the synthesis of monodisperse CdS NCs in the size range of 3.0–5.4 nm, and the NCs produced photoluminescent emissions in the range of 391–463 nm.     

Enhanced solid-state electrogenerated chemiluminescence of Au/CdS nanocomposite and its sensing to H2O2

Au nanoparticles (AuNPs) are good quenchers once they closely contact with luminophore. Here we reported a simple approach to obtain enhanced electrogenerated chemiluminescence (ECL) behavior based on Au/CdS nanocomposite films by adjusting the amount of AuNPs in the nanocomposite. The maximum enhancement factor of about 4 was obtained at an indium tin oxide (ITO) electrode in the presence of co-reactant H₂O₂. The mechanism of this enhancement was discussed in detail. The strong ECL emission from Au/CdS nanocomposites film was exploited to determine H₂O₂. The resulting ECL biosensors showed a linear response to the concentration of H₂O₂ ranging from 1.0 × 10⁻⁸ to 6.6 × 10⁻⁴ mol L⁻¹ with a detection limit of 5 nmol L⁻¹ (S/N = 3) and good stability and reproducibility.     

CdS纳米棒的化学浴沉积法制备和机理研究(英文)

采用化学浴沉积法制备了高纵横比的CdS纳米棒。二苯硫腙(DPTA)作为有机添加剂用于合成CdS纳米棒。用X射线衍射(XRD)和透射电子显微镜(TEM)表征样品的结晶性能和微观结构。XRD结果表明,样品中同时存在六角相和立方相,当pH值为10.5时,六角相CdS的(111)峰的衍射强度最大,同时出现立方相CdS。TEM结果显示,可以通过调节pH值控制CdS纳米晶的形貌,当pH值为10.5时,CdS纳米棒的纵横比最大,直径约50nm,长约3μm。对CdS纳米晶电学性能的研究表明,与用PVA作为添加剂和在纯乙醇中制备的CdS纳米棒相比,用DPTA作为添加剂制备的CdS纳米棒具有更低的电阻值。这是因为DPTA分子中存在2个大π键,有利于电子的传输。还讨论了CdS纳米棒的生长机理和DPTA修饰CdS纳米棒中的电子转移。     

超声诱导乳液介质中花状CdS纳米结构的制备

为考察超声作用和无表面活性剂乳液对合成纳米材料的影响作用,在超声诱导形成的油包水乳液介质中,制备出菊花状CdS纳米结构微球。用SEM,TEM和XRD等对产物进行了表征,考察了反应温度的影响作用,并初步探讨了产物的形成机理。结果表明:CdS纳米结构微球的平均直径为7μm,属于立方晶系,由纳米级的结构单元——直径为140 nm的CdS纳米棒组成;随着反应温度的升高,所合成的CdS纳米结构微球的直径变小。油包水乳液的分散相液滴对CdS纳米结构微球的形成起到空间限定和模板作用。文中报道的方法可望用于其他组成的球状纳米结构的合成。     

硅壳包裹核/壳型CdSe/CdS纳米晶的制备与性能研究

采用低温水热技术,分别以柠檬酸、聚乙二醇(PEG400)和甲硫氨酸为稳定剂,在水相中合成了核壳型CdSe/CdS量子点,研究了稳定剂、CdSe与CdS物质的量比对量子点发光性能和结构的影响。XRD结果表明,当CdSe∶CdS在1∶3~4时,CdS主要在CdSe的外延生长,形成核壳型纳米粒子,当比例达到1∶5时,CdS单独成晶现象严重。CdSe∶CdS=1∶4时,核壳型量子点具有较高的荧光发射效率。TEM研究表明CdS在CdSe外表面生长形成较为完整的壳层,有效钝化CdSe表面,减少表面缺陷,从而显著提高CdSe量子点的发光效率。CdSe核尺寸为2~3nm的核壳型纳米粒子外包裹一层SiO2壳后,荧光发射效率没有显著提高,发射峰位置无明显红移。量子点包壳后能有效提高该量子点的光化学稳定性,提高量子点的生物相容性。     

Facile synthesis of monodisperse ZnS capped CdS nanocrystals exhibiting efficient blue emission

A new method for the capping of colloidal CdS nanocrystals with ZnS shells is presented. A combination of the monomolecular precursor zinc ethylxanthate (Zn(ex)₂) and zinc stearate was used to replace hazardous organometallic reagents usually applied in this procedure, i.e. bis(trimethylsilyl) sulfide and diethylzinc. Its simple preparation, air-stability and low decomposition temperature of 150 °C make Zn(ex)₂ a very suitable source for the ZnS shell growth. With this precursor, highly luminescent CdS/ZnS core/shell nanocrystals (Q.Y. 35–45%), exhibiting narrow emission linewidths of 15–18 nm (FWHM) in the blue spectral region, can reproducibly be obtained.     

硫化镉纳米结构的制备与光学性质研究

采用直接热蒸发CdS粉末的方法,在不同的生长条件下制备出CdS纳米线和纳米带材料并对其形貌、结构和光学性质进行了研究.CdS纳米线具有单晶结构,且生长方向具有择优取向,而其纳米带不具有上述结构特征.光致发光光谱研究发现,室温下纳米线只在508 nm出现了CdS的本征发射带.然而,纳米带存在2个明显的发光峰,中心峰位分别位于513 nm和756 nm.这2个发射峰可分别指认为CdS的本征发射和V_s~+空位引起的发射.