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.     

水浴沉积法制备硫化镉薄膜的初步研究

采用化学水浴沉积法制备了半导体薄膜硫化镉（CdS）太阳能电池材料,对影响成膜的因素以及薄膜的结构和光学性能进行了初步测试研究。结果表明,反应溶液的pH值以及薄膜的退火温度是影响成膜的重要因素。实验中pH值范围控制在10．5—10．8之间,最佳退火温度为400℃。另外退火时滴加CdCl2溶液并将其涂抹于薄膜表面,可以使薄膜在可见光范围的透过率得到进一步的提高。     

On the influence of light on dislocation motion in compound semiconductors

The influence of light on dislocation motion and the associated flow stress is examined for CdS and (Hg_0.3Cd_0.7)Te semiconductors. For CdS, a large increase in flow stress is observed for slip on the basal planes during irradiation. In contrast, (Hg_0.3Cd_0.7)Te exhibits a smaller photoplastic effect with a time delay. Results of experiments on the effect of light, slip direction, strain rate, and temperature are presented with emphasis on CdS. Possible mechanisms of photoplasticity, along with methods of exploiting the photoplastic effect to reduce dislocation densities in semiconductor devices, are also discussed.     

S and Te inter-diffusion in CdTe/CdS hetero junction

Effects of post formation thermal annealing of the CdTe–CdS device on the inter-diffusion of S and Te at the junction in a substrate configuration device have been studied by Auger electron spectroscopy. While the migration of S and Te atoms increases with annealing temperature, the extent of S diffusion is always higher than the diffusion of Te atoms. Inter-diffusion of S and Te causes the formation of CdTe_1-xS_x ternary compound at the CdTe–CdS interface.     

Growth modes of solution-grown CdS thin films

The growth modes of CdS thin films on glass in a chemical bath were analysed using scanning electron microscopy and optical microscopy. The results of these studies show that the film growth occurs by ion-by-ion condensation and by colloidal particles of CdS adhering to the substrate. Both mechanisms are operative from the initial stages of film growth. The predominance of one or other of these two growth modes depends on the abundance of Cd and S ions present in the solution, which is determined by the amount of complexing and sulphurising agents and ammonia used for the controlled release of Cd and S ions into the solution. The growth mode influences the optical properties of the films.     

CdS半导体非线性吸收中的电场作用

在CdS的室温光学非线性吸收过程中,再外加直流电场,观察到光学非线性吸收随外场增大而增大,非线性出现的光强阈值随外场增大而减小.通过实验判断这一现象来源于电子激子散射.     

ZnCdS films for solar cell and photodetector applications deposited by In Situ chemical doping of CdS with Zn

ZnCdS films were formed by in situ chemical doping of CdS with Zn in a chemical bath. The X-ray diffraction (XRD) patterns of CdS films after Zn doping showed a more disordered nature, consisting of reflections from Zn_0.049Cd_0.951S (JCPDS 40-834) as well as CdS greenockite (hexagonal, JCPDS 41-1049) and hawleyite (cubic, JCPDS 10-0454) phases. A comparison of the optical transmittance spectra for undoped and Zn-doped films showed that the cut-off wavelength was modified after Zn doping, indicating the presence of impurity states in the band gap. Zn-doped films showed an increase in dark conductivity after annealing at about 200°C. These films exhibit promising characteristics for application in solar cell and photodetector structures.     

Nanostructured Cadmium Sulfide： Sonochemical Synthesis,Optical Properties and Formation Process

Semiconductor CdS nanoparticles were synthesized by the sonochemical reduction of a mixed aqueous solution of CdCl2, Na2S2O3 and (CH3)2CHOH in Ar atmosphere at room temperature. The results of a detailed investigation with X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectrum and optical absorption spectroscopy are reported. A clearly red shift of the absorption edge and a broad absorption band related to the surface states of nanoparticles have been observed in the optical absorption spectra with the increasing of CdS particle size.The mechanisms of the CdS nanoparticle formation and size growth during sonochemical irradiation were discussed.This convenient method is found to be an efficient way to produce other chalcogenides as well.     

Surface photochemistry: efficient photocatalysis by CdS supported on a solid surface

The photocatalytic efficiency of a series of CdS samples: (i) a colloidal solution in aqueous CH₃CN; (ii) suspensions of (a) supported colloidal particles, (b) bulk CdS, and (c) commercial powders, was compared with respect to stilbenec-t isomerization. The samples of type (ii a), prepared from cadmium chloride and H₂S showed a high photocatalytic activity, attributable to the combined effects of the catalyst particle size and the presence of chloride ions. Increased activity over the commercial sample was also shown in the conversion of hexamethyl(dewar)benzene to hexamethylbenzene, and in the cleavage of anthracene dimer. It has been found that bulk CdS is activated by grinding with < 10% of certain metal chlorides and bromides.     

A CCD-based reader combined with CdS quantum dot-labeled lateral flow strips for ultrasensitive quantitative detection of CagA

Immunochromatographic assays are widely used to detect many analytes. CagA is proved to be associated closely with initiation of gastric carcinoma. Here, we reported that a charge-coupled device (CCD)-based test strip reader combined with CdS quantum dot-labeled lateral flow strips for quantitative detection of CagA was developed, which used 365-nm ultraviolet LED as the excitation light source, and captured the test strip images through an acquisition module. Then, the captured image was transferred to the computer and was processed by a software system. A revised weighted threshold histogram equalization (WTHE) image processing algorithm was applied to analyze the result. CdS quantum dot-labeled lateral flow strips for detection of CagA were prepared. One hundred sera samples from clinical patients with gastric cancer and healthy people were prepared for detection, which demonstrated that the device could realize rapid, stable, and point-of-care detection, with a sensitivity of 20 pg/mL.