Nanocrystalline PbS thin films are deposited on glass and alumina substrates
through the chemical bath deposition technique by creating similar conditions, in order
to investigate the effects of the substrate. The structural and optical properties of PbS
films are investigated by X-ray diffraction, scanning electron microscope, and UV–Vis.
The structural analyses of the films indicate that they are of polycrystalline
configurations and have a face-centered-cubic (fcc) rock-salt structure on different
substrates. The X-ray diffraction shows that the structure peaks occur at slightly higher
angles in the deposited (grown) films on glass substrate than the ones deposited on
alumina substrate. Crystal parameters are exceptionally affected by the type of substrate
as well. SEM images reveal that the surface morphology of the PbS thin films is quite
dependent upon the nature of the substrate. The optical band gaps of the samples are
found to be 1.521 eV for glass and 1.678 eV for alumina substrates, which are higher in
comparison to the bulk value (0.41 eV). According to the obtained results, PbS thin film
on alumina substrate has narrower particle size distribution, better transmission and
lower stress than PbS thin film on glass substrate. تفاصيل المقالة