Deposition and characterization of PbO--PbS multilayer thin films by solution growth technique

Authors: DOMINIC EYA

Abstract: PbO-PbS thin films were deposited on glass substrates using the chemical bath deposition (CBD) technique. PbO thin films were deposited from the solution of lead nitrate (Pb(NO_3)_2) and sodium hydroxide (NaOH). Ethylenediaminetetraacetate (EDTA) served as the complexing agent. Some of the PbO films were used as substrate for the deposition of PbS. The PbS was deposited from alkaline solution of lead nitrate and thioacetamide. Triethanolamine was used as the complexing agent. Some of the films were subjected to thermal treatment after deposition. Energy dispersive X-ray fluorescence analysis confirmed the presence of Pb and S in the PbS thin films, while Rutherford backscattering was used to identify the composition of PbO thin films. The absorbance of PbO-PbS films was extremely high in the UV region and decreased exponentially with increase in wavelength. The transmittance increased sharply but almost linearly with wavelength from the mid-vis region, having a maximum percentage value of 21% at 1000 nm (NIR). Hence, PbO-PbS films are good materials for UV filters and glazing for creating warmth in rooms. The band gap of PbO-PbS films is in range 2.15-2.25 eV.

Keywords: PbO-PbS, chemical bath deposition, thin film, annealing, multilayer, band gap

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