Thick film technology offers advantages of low cost, product amenability and automation. This technology has been successful in the manufacture of solar cells using CdS/CdTe heterojunctions. It enables the use of the same equipment in various processes involved in manufacturing solar cells. In the present work, n-CdS/p-CuInSe2 solar cells are prepared by screen printing and sintering pastes which contain the semiconductors. An efficiency of 8.75% is achieved. Electron affinity difference, saturation current and diode quality factor are measured. They are 0.49 eV, (0.9–1.8)×10-7 A, 1.5 respectively. Microstructure and electrical properties of sintered CdS films containing 10, 20, 30 and 40 wt% CdCl2 are investigated. Optimum results are obtained for the CdS films containing 10 wt% CdCl2.

No abstract

The effect of electron beam irradiation on the structure and optical properties of a PM-355 solid-state nuclear track detector has been investigated. Samples from PM-355 were irradiated with electron beams with different doses ranging from 20 to 250 kGy. The structural and optical modifications in the electron beam-irradiated PM-355 samples have been studied as a function of dose using different characterization techniques such as Fourier transform infrared spectroscopy, Vickers hardness, refractive index and color difference measurements. The Commission International de E'Claire (CIE units x, y and z) methodology was used in this work for the description of colored samples. In addition, the color differences between the non-irradiated sample and those irradiated with different electron beam doses were calculated. The results indicate that the PM-355 detector acquires color changes under electron beam irradiation.

No abstract

No abstract

Makrofol-De polycarbonate is a class of polymeric solid state nuclear track detector which has many applications in various industrial fields. A study of the modification possibility of the dielectric properties of a Makrofol polymer using laser irradiation has been carried out. In the present work, Makrofol samples were irradiated using different fluences between 0.47 and 10.4 J/cm 2 of 5 W infrared laser. The modifications in the laser irradiated Makrofol samples have been studied as a function of fluence using dielectric constant ε , dielectric loss ε , and AC conductivity σ AC measurements. The frequency dependencies (100 Hz-5 MHz) of ε , ε and σ AC at 35 • C were investigated. The dielectric constant ε , dielectric loss ε and AC conductivity σ AC were also found to increase on heating up to 100 • C. The results indicate that ε , ε and σ AC depend not only on the frequency and temperature but also on the laser fluence.

Samples from sheets of the polymeric material Bayfol DPF 5023 have been exposed to X-ray radiation in the dose range 100-2300 Gy. The modifications induced in Bayfol samples due to X-ray irradiation have been studied through different characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, intrinsic viscosity, refractive index and color difference studies. The infrared spectroscopy indicated that crosslinking is the dominant mechanism at the dose range of 200-2300 Gy. The crosslinking reported by FTIR spectroscopy destroyed the degree of ordering in the Bayfol samples, as revealed by the XRD technique. Also, this crosslinking led to an increase in the value of intrinsic viscosity from 0.54 for the non-irradiated sample to 0.63 for the sample irradiated with 2300 Gy at 30 • C, indicating an increase in the average molecular mass. This was associated with an increase in the refractive index. Additionally, the non-irradiated Bayfol samples showed significant color sensitivity toward X-ray irradiation. This sensitivity appeared in the change of the blue color component of the nonirradiated Bayfol film to yellow after exposure to X-ray doses up to 2300 Gy. This is accompanied by a net increase in the darkness of the samples.

The electron affinity difference AEc = Xl -;t2, in CdS/CdTe solar cells fabricated by four different processes has been measured from observations of the variations of open voltages with temperature. For CdS/CdTe cells, the values of AEc lie between 0.20 and 0.25 eV and are found to be independent of the process of cell fabrication. The use of CdZnTe in place of CdTe increases the value of AEc to 0.49 eV. The method used for the measurement of AE~ is very simple. The values of the saturation current Io for the different types of cells have been estimated from the slopes of qVo~ versus kT plots and compared with those obtained from lnI versus V curves. The values of I0 found for each cell by the two methods are in substantial agreement.