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Autori: Emil Indrea , Adriana Barbu
Editorial: ELSEVIER, Applied Surface Science, 106, p.498 - 501, 1996.
A sensitization process by heat treatment in oxygen atmosphere was used in order to increase the photoconductivity of
vacuum evaporated PbS thin films. The Fourier analysis of the (200) PbS X-ray diffraction profile has shown a decrease of the crystallites mean size and an increase of the sensitized PbS lattice distortion because of chemisorption of oxygen at the
crystallites surfaces. The crystallites mean size distribution function indicates that the sensitized PbS film is a heterogeneous
system of 320 A size crystallites separated by 160 A intercrystalline barriers. The optical photoacoustic spectra of the sensitized PbS film shows an absorption structure at low photon energies of the 0.47 eV absorption threshold. The
broadening effect observed in the absorption spectrum suggests an indirect photon transitions in the fundamental absorption region.
Cuvinte cheie: fotodetectori PbS , fotoconductivitate , difractie raze X , tehnica fotoacustica // PbS photodetectors , photoconductivity , X-ray diffraction , photoacoustic technique