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Abstract
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PbS nanocrystalline thin film was prepared by chemical bath deposition on Si
(1 0 0) substrate at bath temperatures of 25, 45 and 65 °C. Triethanolamine
was added to the aqueous solution, which decreased the grain size and
increased the luminescence of the nanocrystalline PbS thin film. PbS nanocrystals
were identified using XRD, TEM and AFM. The crystalline size of
the PbS film deposited at different bath temperatures was estimated by XRD
and TEM to be 7–12 nm. The growth mechanism of the PbS crystallites were
described at different bath temperatures. The confinement was reflected in the
absorption spectra, photoluminescence excitation and photoluminescence
spectra. The luminescence of Si(1 0 0) substrate and PbS nanocrystalline
film deposited on Si(1 0 0) were compared, and the results revealed that
the PbS nanocrystals altered and notably enhanced the emission features of
the Si(1 0 0) substrate. The shifting of the maximum photoluminescence
emission wavelength of PbS nanocrystals with a change in bath temperature
and the variation in photoluminescent intensity of PbS nanocrystals prepared
at 25 °C versus deposition time were investigated. A single-peak fit of a
Gaussian function was employed to discern the photoluminescence of PbS on
Si(1 0 0) substrate.
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