激光刻蚀模板中电沉积特殊结构CIGS薄膜

本文利用激光刻蚀模板,在水溶液中电沉积制备金属铜薄膜,讨论了温度、电流、硫酸铜浓度对薄膜形貌的影响. 采用SEM对制备的铜薄膜进行表征,结果表明在沉积温度为30 ℃,沉积电流为4 A·dm^-2(表观工作电流密度),硫酸铜浓度在20 ~ 50 g·L^-1的水溶液中电沉积可以得到中空馒头状和开口碗状结构的铜薄膜. 利用激光刻蚀模板,在离子液体1-丁基-3-甲基咪唑三氟甲磺酸盐([BMI][TfO]) - 30 Vol%丙醇混合电解质中电沉积CIGS薄膜,研究了沉积电势、沉积时间对薄膜形貌的影响. SEM观察发现,在沉积电势为-1.8 V,沉积时间为1.5 h条件下电沉积可以得到近似柱状的簇状花束样的CIGS薄膜, 电沉积铜后再进一步电沉积CIGS,得到了均匀有序的鼓包柱状结构的Cu/CIGS复合薄膜. 用恒电势方波法对制备的薄膜真实表面积进行测试,计算结果表明,与无模板电沉积制备的CIGS薄膜相比,激光刻蚀模板法制备的Cu/CIGS复合薄膜的表面积提高了约8倍.     

Transmission Electron Microscopic Investigation of the Morphology of High-Speed Spun Poly(Ethylene Terephthalate) Fibers

Permanganic etching was performed on high-speed spun (HSS) and regular fibers of poly(ethylene terephthalate) (PET), and their surface morphologies were investigated via the two-stage carbon replica method using a transmission electron microscope (TEM). The HSS PET fibers, with disordered amorphous regions, showed peculiar surface morphology; many small warts corresponding to the pits of etched disordered amorphous regions were observed. Such unevenness, however, was hardly observed on the surface of the permanganic-etched regular PET fibers, with well-oriented amorphous regions, or on the surface of alkali-etched HSS PET fibers. The permanganic etchant removed the disordered amorphous regions more preferentially compared with the alkali etchant.     

Use of chemical etching of CR-39 foils at elevated temperature for fast neutron personnel monitoring in India

CR-39 Solid State Nuclear Track Detecting foils (SSNTD), along with 1 mm thick polyethylene radiator, sealed in triple laminated pouches, are used for country wide Fast Neutron Personnel Monitoring in India. With the present system of processing by elevated temperature electrochemical etching (ETECE) and evaluation using automatic image analysis, only 16 foils are processed at a time and it is useful over the dose equivalent range 0.2 mSv to 10 mSv. It has been reported that, by processing CR-39 of good detection efficiency by chemical etching at elevated temperature, more numbers of foils can be processed simultaneously. In the present study, CR-39 foils from Pershore Moulding (UK) have been chemically etched using 7 N KOH under various conditions of temperature and etching durations and evaluated using high magnification microscope. The duration of chemical etching, has been optimized at a constant temperature of 60°C for chemical etching process. The characteristics of the chemically etched CR-39 foils are compared with the characteristics of the CR-39 foils processed by the existing system of ETECE and the detailed results are presented in the full text of the paper. It has been observed that by chemical etching process, the dose equivalent range of CR-39 foils can be extended above 60 mSv.      

The effect of pre-pattern on the morphology and growth speed of TiO2 nanotube

In this work, we presented a new method which directly acts on the surface of the Ti sheet by mechanical micro-etching using a grating ruling engine. The effect of the pre-pattern on the morphology and growth speed of TiO₂ nanostructure formed on the Ti sheet with the traditional anodization method was investigated. A novel wall structure was observed and the growth speed of TiO₂ nanotube (NT) was greatly affected by the pre-pattern. The wall structure increases the surface-to-volume ratio of the nanotube arrays. The new method provided the possibility of further optimization of fast growth of TiO₂ nanostructure and improving the efficiency of dye-sensitized solar cell (DSSC) and photocatalysis.     

Etching and annealing studies of nuclear tracks in glasses

A series of etching and annealing experiments are designed to evaluate the characteristics of fission tracks in a number of glasses of varying silica content. A comparative study has been made by comparing the calculated value of bulk etch rate, optimum etch time and annealing rate for each glass. The present investigation suggests that both bulk etch rate (V_G) and annealing rate (V_a) increases with the decrease in silica content of glasses. A minimum value of these parameters is observed for pure silica glass.     

Measurement of photoneutron doses in and out of high-energy X-ray beam of a SATURNE-20 medical linear accelerator by ECE polycarbonate detectors

Photoneutron contaminations in and out of high energy X-ray beams of the medical linear accelerator SATURNE 20 (CGR) of the Radiotherapy Department of Omeed Hospital in Isfahan, Iran, have been determined using 250 μm polycarbonate (PC) dosimeters, in strips or in sheets, processed by electrochemical etching (ECE) using specially designed ECE chambers to etch larger sheets. A two dimensional or topographical distribution of neutron contamination was also determined in a full size beam. The neutron dose equivalents (Hn) in the beam of 18 MV X-rays at 80 cm FSD were determined to be linear functions of X-ray dose equivalents (Hx) up to 1400 cSv. The distribution of the Hn at different X-ray doses showed bell-shape profiles with maxima at the isocenter. The ratios of dose equivalents of neutrons to those of X-rays increased as the field size increased having values of 0.22%, 0.28%, 0.31% and 0.37% for field sizes of 10×10, 20×20, 30×30, and 40×40 cm² respectively. Although such neutron dose equivalents can be corrected for patient treatment, it can cause radiation protection problems for workers where the design of the facility is not well planned.     

Determination of concentrations of fissionable elements in the Black Sea sediment samples before and after Chernobyl using neutron radiography method

The fissionable elements content, particularly uranium, of the Blask Sea sediment samples obtained in 1978 and 1989 as surfacial sediments were determined by neutron radiography using solid state nuclear track detectors (SSNTDs).     

Tracks of 18·56 MeV/u 40Ar ions in Lexan polycarbonate detector

Latent damage tracks of energetic⁴⁰Ar ions (18·56 MeV/u) have been recorded in Lexan polycarbonate detector. Bulk and track-etch parameters are evaluated under successive chemical etching. Our results show a linear correlation between the measured track-etch rate along the track and the corresponding total energy-loss rate and predict a threshold value of 5·0 MeV mg⁻¹ cm² for track registration. Maximum etchable track lengths of⁴⁰Ar ions as a function of energies have also been measured and compared with three different sets of theoretical ranges.