48 research outputs found
Optical and Optoelectric Properties in PbCdS Ternary Thin Films Deposited by CBD
PbxCd1-xS films have been prepared in the composition range of 0.05ÂŁ xÂŁ0.25by using a chemical bath deposition growth technique under optimum conditionsto deposit good photo response. X-ray diffraction study results show that the filmsare of PbS-CdS composite with individual CdS and PbS planes. The filmsexhibited two direct band gaps, 2.4 eV belongs to CdS, and the second variescontinuously from 2.4eV to 1.3eV. The surface morphology of the films is smoothwith crystallite of increasing grain size with increasing the mole fraction (x). Thedecrease in the band gap with increase in lead concentration suggests that theComposite of PbS (Eg=0.41eV) with CdS (Eg=2.4eV)
Growth of PbTe films by laser induced evaporation of pressed PbTe pellets
PbTe films have been deposited on glass substrates by laser ablation from
PbTe pellets pressed from high purity Pb and Te powder. X-ray diffraction
experiments and optical characterization of the films have been performed as
a function of evaporation conditions (pellet composition and substrate
temperature). From transmittance and reflectance measurements the values of
the absorption coefficient , of the refractive index n, and of the
extinction coefficient k have been calculated
Thermally stimulated current measurements on polycrystalline PbI
Thermally stimulated current measurements have been performed on polycrystalline
layers of lead iodide grown from solution. Several TSC peaks or bands have been observed at
temperatures of 100 K, 195–220 K, 230–240 K and 270–300 K. Comparison with PbI2 single
crystal shows that the polycrystalline structure of the material introduces additional defects. In
contrast the defect currently found in single crystal and attributed to the lead vacancy has not
been clearly evidenced in the polycrystalline layers. The position and relative intensity of the
peaks can be modified by Ag doping and thermal annealing. On the other hand, only small
differences resulting from the anisotropy of the material have been observed depending on the
orientation of the electric field with regards to the grains orientation
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Ionization Loss of Channeled 1.35-GeV/c Protons and Pions
The channeling effect has been observed to reduce the ionization energy loss by about a factor of 3 for 1.35-GeV/c protons and π+ traversing a 0.67-mm germanium crystal.Physic