CdS量子点的优化合成及其在离子检测中的应用

实验探讨了采用胶体法合成荧光CdS QDs的一些因素.对样品进行了TEM、XRD、UV-vis等表征.将合成的QDs应用于Cu2 检测,并探讨了作用机理.     

PET/PbS纳米复合材料的热降解动力学研究

利用双螺杆挤出机挤出造粒制备了共混型PET/PbS纳米复合材料,并利用热失重(TG)方法研究了PET/PbS和纯PET在空气气氛下的热降解行为,发现PET/PbS和纯PET的热降解过程相似。利用Flynn-Wall-Ozawa法对数据进行处理,结果表明,在失重30%以前,PET/PbS-1(PbS质量分数1%)的降解活化能高于PET的活化能;当失重率在30%～70%时,PET/PbS-1的降解活化能小于PET的降解活化能。在降解前期,由于纳米PbS对PET分子链的某种限制作用,使得复合材料的活化能略高于纯PET;但在后期,PbS催化降解作用占据主导作用,使得复合材料的活化能低于纯PET,稳定性下降。     

硫化铅红外探测器光电性能自动测试系统设计

简要介绍了硫化铅红外探测器光电性能自动测试系统的构造及设计思路。与传统的测试设备相比,自动测试系统具有测试快速准确、操作简单、可靠性高等显著特点。     

Cu掺杂对ZnO量子点光致发光的影响

通过溶液法合成了Cu掺杂ZnO量子点。X射线衍射(XRD)和高分辨电子透射电镜(HRTEM)图像显示Cu掺杂ZnO量子点具有六角纤锌矿结构,晶粒大小为4～5nm。Cu掺杂抑制了ZnO量子点颗粒长大。室温光致发光(PL)谱观察到紫外带边和可见区两个发射峰。随着Cu掺杂浓度的增大,紫外荧光峰位发生缓慢红移,由366nm移到370nm;可见区发射峰位发生蓝移,由525nm移到495nm;同时,两个发射峰强度降低。光谱结果表明:Cu的掺入,一方面抑制表面与O空位有关的缺陷,在495nm出现了与Cu1+有关的发射峰;另一方面,Cu离子掺入ZnO量子点引入一些非辐射中心,降低了自由激子发射。     

提高硫化铅红外探测器的探测率和可靠性的有效途径

本文通过对不同结构的硫化铅红外探测器的剖析和性能优劣对比,说明了新型场镜—硫化铅组合结构是提高硫化铅红外探测器的探测率和可靠性的有效途径。     

Protein A Detection Based on Quantum Dots-Antibody Bioprobe Using Fluorescence Coupled Capillary Electrophoresis

In this report, fluorescence detection coupled capillary electrophoresis (CE-FL) was used to detect Protein A. Antibody was first labeled with Cy5 and then mixed with quantum dots (QDs) to form QDs-antibody bioprobe. Further, we observed fluorescence resonance energy transfer (FRET) from QDs donor to Cy5 acceptor. The bioprobe was formed and brought QDs and Cy5 close enough to allow FRET to occur. After adding protein A, the FRET system was broken and caused the FRET signal to decrease. Thus, a new method for the determination of protein A was proposed based on the FRET signal changes. This study provides a new trail of thought for the detection of protein.     

Tuning light emission of PbS nanocrystals from infrared to visible range by cation exchange

Colloidal semiconductor nanocrystals, with intense and sharp-line emission between red and near-infrared spectral regions, are of great interest for optoelectronic and bio-imaging applications. The growth of an inorganic passivation layer on nanocrystal surfaces is a common strategy to improve their chemical and optical stability and their photoluminescence quantum yield. In particular, cation exchange is a suitable approach for shell growth at the expense of the nanocrystal core size. Here, the cation exchange process is used to promote the formation of a CdS passivation layer on the surface of very small PbS nanocrystals (2.3 nm in diameter), blue shifting their optical spectra and yielding luminescent and stable nanostructures emitting in the range of 700–850 nm. Structural, morphological and compositional investigation confirms the nanocrystal size contraction after the cation-exchange process, while the PbS rock-salt crystalline phase is retained. Absorption and photoluminescence spectroscopy demonstrate the growth of a passivation layer with a decrease of the PbS core size, as inferred by the blue-shift of the excitonic peaks. The surface passivation strongly increases the photoluminescence intensity and the excited state lifetime. In addition, the nanocrystals reveal increased stability against oxidation over time. Thanks to their absorption and emission spectral range and the slow recombination dynamics, such highly luminescent nano-objects can find interesting applications in sensitized photovoltaic cells and light-emitting devices.     

硫化铅纳米粒子的三阶非线性光学特性研究

针对硫化铅(PbS)特殊的三阶非线性光学特性,本文在水溶液里合成了PbS纳米粒子.紫外-可见光谱显示,由于使用了封端剂,合成的样品更加稳定.用紫外-可见吸收光谱和X射线衍射斑研究了PbS纳米粒子的特性,结果表明,由于纳米粒子尺寸减小,其吸收光谱显示极大的蓝移.利用Seherre方程估计PbS粒子的平均粒径约为8.2 n...     

Microstructured extremely thin absorber solar cells

In this paper we present the realization of extremely thin absorber (ETA) solar cells employing conductive glass substrates functionalized with TiO₂ microstructures produced by embossing. Nanocrystalline or compact TiO₂ films on Indium doped tin oxide (ITO) glass substrates were embossed by pressing a silicon stamp containing a μm size raised grid structure into the TiO₂ by use of a hydraulic press (1 ton/50 cm²). The performance of these microstructured substrates in a ETA cell sensitized by a thermally evaporated or chemical bath deposited PbS film and completed by a PEDOT:PSS hole conductor layer and a Au counter electrode is compared to that of planar substrates. Surprisingly planar films produced better performance than micro-structured films. A simple model implying photoconductive shunting paths revealed by junction breakdown at negative bias under illumination is presented.