ZnO/ZnSe复合纳米结构的制备及可见光光催化性能

通过热水解法, 以氧化锌为模板, 成功制备出形貌均一的ZnO/ZnSe复合纳米结构. 为了对比不同O/Se比对光催化性能的影响, 保持其它反应参数不变, 调节还原剂水合肼的用量, 得到不同硒化程度的ZnO/ZnSe复合纳米结构. 采用场发射扫描电子显微镜、 X射线衍射仪和透射电子显微镜对样品的形貌及结构进行了表征, 通过测试该复合结构对亚甲基蓝的可见光催化降解评估了其光催化效率. 结果表明, 与纯ZnO比, ZnO/ZnSe复合结构在可见光区域和紫外光区域的光吸收范围变宽, 显示出较高的光催化效率. 原因在于ZnSe导带上的电子在扩散势能的作用下迁移到ZnO的导带上, 而空穴仍保留在ZnSe价带, 这样有助于光生电子和空穴对的分离, 降低其复合机率, 从而提高ZnO的光催化效率.     

Luminescence properties of Cr:ZnSe: Comparison between a single crystal and a film deposited by RF magnetron co-sputtering

We investigated the optical properties of a Cr²⁺:ZnSe film deposited by radiofrequency magnetron co-sputtering and compared them with those of a single crystal. The mid-infrared room temperature photoluminescence spectra under direct (1850 nm) and indirect (458 nm) excitation revealed that chromium has been incorporated in the Cr²⁺ active state. The difference of Cr²⁺ fluorescence lifetime values (measured between 10 and 400 K) between both samples was attributed to the presence in the film of firstly a large amount of chromium in a valence state different from the Cr²⁺ active state and secondly structural defects in the ZnSe host matrix. Visible photoluminescence measurements were carried out in order to identify these structural defects.     

Synthesis of Functionalized ZnSe Nanoparticles and Their Applications in the Determination of Bovine Serum Albumin

Luminescent quantum dots (QDs)-semiconductor nanocrystals were promising alternative to organic dyes for fluorescence-based applications. In this paper, we developed procedures to use mercaptoacetic acid (MAA) to modify ZnSe nanoparticles and made the nanoparticles to be soluble for the quantitative and selective determination of bovine serum albumin (BSA). Maximum fluorescence intensity was produced at pH 7.0, with excitation and emission wavelengths at 242 and 348 nm, respectively. Under optimal conditions, the straight line equation: ^△ F = 0.38 + 0.34 C (μg/ml) was found between the relative fluorescence intensity and the concentration of BSA in the range of 9.6–124.8 μg/ml, and the limit of detection was 2 μg/ml.     

Design and fabrication of ultra broadband infrared antireflection hard coatings on ZnSe in the range from 2 to 16 μm

In conventional infrared multilayer antireflection coatings (MLAR) materials of fluoride and chalcogenide types are used, which are disadvantaged due to their low mechanical strength and poor stability against humidity and environmental impacts. In this paper, we show that high performance ultra broadband and hard infrared multilayer antireflection coatings on ZnSe substrates in the wavelength range from 2 to 16 μm can be designed and fabricated. Diamond-like carbon (DLC) hard coating as a mechanical and environmental protection layer was proposed and deposited onto MLAR surfaces (MLAR + DLC) using a pulsed vacuum arc ion deposition technique. The thickness of the high optical quality DLC can be optimized in the design simulation to achieve a practically best antireflection and surface protection performance. We show that a germanium thin film (15 nm) between the MLAR and DLC surfaces can be used as a transition layer for optical and material match. The average transmission of the fabricated MLAR+DLC surfaces was 93.1% in the wavelength range between 2 and 16 μm. The peak transmission was about 97.6%, close to the simulated values. The durability and stability against mechanical impacts and environmental tests was improved significantly compared with the conventional infrared windows.     

激光／红外双波段减反射膜研究

在硫化锌、硒化锌两种基底上开展了激光／中波红外、激光／长波红外双波段减反射膜技术研究。通过采用离子辅助沉积以及镀保护膜层等方法,对膜系结构和镀制工艺进行了优化。研制的激光／红外双波段减反射膜不仅具有良好的光学性能,而且具有较强的抗恶劣环境能力,可以满足实际使用要求。     

Thermal conductivity of ZnSe by molecular dynamics simulation

Molecular dynamics simulation using the new fit of the empirical Tersoff Potential is applied to study the thermal properties of ZnSe at and below the room temperature. The resulting diffusivity and thermal conductivity are compared with the photoacoustic measurements on the grown ZnSe crystal. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

以S、Se为原料的CVD ZnS、CVD ZnSe的化学反应分析

本文详细分析了用单质硫或单质硒为原料,在Zn-S-H2-Ar体系或Zn-Se-H2-Ar体系中化学气相沉积生长 ZnS和ZnSe晶体所发生的化学反应,认为在这两种化学气相沉积过程中所发生的化学反应是以锌蒸汽与硫或硒蒸汽反应来实现的.计算出了上述反应的△H、△S和△G这些热力学函数,并将该△G与采用H2S气体(Zn-H2S-Ar体系)和H2Se气体(Zn-H2Se-Ar体系)为原料的CVD ZnS和ZnSe做了对比.实验结果表明,以单质Se为原料生长的CVD ZnSe比以H2Se为原料的CVD ZnSe的努普硬度有显著的提高.     

ZnSe－CdZnse多量子阱光双稳器件的研制

本文采用电化学选择性腐蚀工艺对ＧａＡｓ衬底蚀孔，在其上获得了大面积具有光滑表面的Ⅱ－Ⅵ族半导体多量子阱外延膜．通过在其表面蒸镀反射膜，制成了高质量的Ｆ－Ｐ腔，制备出ＺｎＳｅ－ＣｄＺｎＳｅ多量子阱Ｆ－Ｐ腔光双稳器件．     

ZnO(n)/ZnSe(i)/c-Si(p)异质结太阳电池的模拟研究

近年来,HIT(heterojunction with intrinsic thin-layer)结构太阳能电池由于具有转化效率高和可低温生产等优点获得了广泛的关注,但是转化原材料成本高、生产技术条件苛刻和缺陷态控制等问题制约了其进一步的发展。本文采用AFORS-HET软件模拟了ZnO(n)/ZnSe(i)/c-Si(p)异质结太阳电池结构吸收层掺杂浓度、缺陷密度和界面缺陷态密度等参数对该结构短路电流、开路电压、填充因子和光电转换效率的影响。优化后的结果显示,当吸收层掺杂浓度为1×10²¹ cm^-3,ZnO层和c-Si层缺陷密度小于10¹⁷ cm^-3时,ZnSe/c-Si界面缺陷密度小于10²⁵ cm^-3时,该结构太阳能电池光电转换效率可达24.29%。     

Low temperature synthesis of metal chalcogenide nanoparticles in mesitylene

We report a new method for the synthesis of zinc and cadmium chalcogenide nanoparticles. The materials are prepared in mesitylene using phosphines, phosphine oxides or amines as capping agents. The low temperature (150 °C) and low concentrations of capping agent, and the use of conventional solvents make this method of particular interest for the manufacture of nanomaterials. Furthermore, the data reported here allow trends in reactivity to be studied and also allow the synthesis of ZnSe which is typically prepared at >250 °C.