Growth and characterization of CdZnS thin film buffer layers by chemical bath deposition
In this paper we report the study of CdZnS thin films grown on the soda-lime glass (SLG) substrates by chemical bath deposition (CBD) process for buffer layer applications in CuGaSe/sub 2/ (CGS) solar cells. Structural, surface morphology, optical, and electrical properties of as-deposited CdZnS films were investigated by XRD, SEM, spectrophotometer, and four probes resistivity measurements as a function of Zn-composition in the solution. The CdZnS films have hexagonal structures. The grain size of CdZnS films was found to increase with increasing Zn-content in the solution. The films with 30% of Zn in the solution showed a better than 80% transmittance for wavelengths longer than 600 nm and film thickness less than 50 nm. The values of energy band gaps obtained are 2.40, 2.55, and 2.70 eV for Zn-content of 0, 30, and 50%, respectively. The resistivity of CdZnS films was found to increase as the Zn content increases.
Kinetics of Growth and Structural Characterization of Cd1-Xznxs Thin Films Synthesized By Cbd Method
In this paper, we reported the study of Cd 1-xZnxS thin film which have been deposited on glass substrates by Chemical Bath Deposition (CBD ) technique by using Cadmium sulphate, Zinc sulphate, thiourea, Ammonia and EDTA. The thickness of Cd 0.5Zn0.5S thin films with different deposition times, pH, and temperature are also study and show increase with increasing times pH, and temperature. The optimum condition to prepared Cd0.5Zn0.5S thin films were obtained in times 3h, temperature 80 oC, and pH 10. Structure and surface morphology of Cd 1-xZnxS thin films were characterized by X-ray diffraction (XRD), Atomic Force microscope (AFM), and Scanning Electron Microscopy (SEM) Measurements. The XRD indicates that all the grown films show only one diffraction peak located at (2 θ= 26.7 ° ) with hexagonal structure in predominant (002). The average grain size changes from 9.3nm to 4.48nm with the increase in zinc content (x = 0 to 0.65). It was found that as the zinc content increases, the peak intensity decreases and for (x ≥ 0.7) the films have amorphous character. The values of lattice constant 'a' and ' c' have been observed to vary with composition from 5.75 nm to 4.68 nm and 6.66 nm to 6.62 nm, respectively, with the increase in zinc content (x = 0 - 0.65). The AFM studies showed that the smooth surface texture was observed in the deposited Cd1-xZnxS films with x= 0.3, the surface roughness of the Cd1-xZnxS thin films is about 2.66nm to 9.47nm and the root mean square (RMS) is about 3.41nm to 11.9nm with increase in zinc content x = 0.3 to 0.6. The SEM exhibits that grains in the film are distributed to cover the surface of the substrate completely, the grains become small in diameters with increasing Zn-contents.
Mathematical Simulation of Combustion of Boron Powder Gas Suspension
Based on a two-phase two-velocity model of a reacting gas-dispersed medium, a mathematical model of combustion of a boron powder gas suspension has been formulated. The results of numerical solution of the problem are presented. The influence of the composition of the gas suspension, its size, size distribution of particles, mass concentration of particles, as well as of the presence of aluminum powder in the suspension on the visible and normal velocities of flame propagation in the gas suspension, is shown. A comparison of the results of calculation with the well-known experimental and theoretical data is carried out. Satisfactory agreement of the predicted results with experimental data is shown.