CHARACTERIZATION OF PbS FILM PRODUCED BY CHEMICAL BATH DEPOSITION AT ROOM TEMPERATURE

Abstract

PbS film has been produced by chemical bath deposition (CBD) method onto glass substrates using aqueous solution containing Pb(NO 3 ) 2 , Na 2 SO 3 , NaOH and SC(NH 2 ) 2 . The deposition was carried out at room temperature of 26°C and a stirring speed of 60 rpm for an hour. The PbS film has been characterized by x-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and optical absorption spectroscopy techniques. The PbS film is polycrystalline face centered cubic phase having randomly preferential orientation in the [101], [200], [220] and [400] directions. The texture coefficient, lattice parameter, strain, crystallite size, and dislocation density were estimated from x-ray diffraction results. Fourier transform infrared result reveals that the presence of PbS and various functional groups in PbS sample. Raman spectrum of the sample shows PbS phase and lead oxysulfates. The optical band gap of the PbS film has been studied using the optical absorbance measurement as a function of wavelength between 200 and 2750 nm. The optical direct band gap of the sample is calculated to be 1.28 eV. The optical band gap of PbS sample exhibited a blue-shift compared with that of bulk PbS.