Praseodymium doped PbS thin films for optoelectronic applications prepared by nebulizer spray pyrolysis

Abstract

Simple nebulizer spray technique used pristine and rare earth praseodymium (Pr) doped PbS thin films coated on soda-lime glass and their optoelectronic properties are reported. Dopant concentration-dependent structural, morphological, optical, and electrical properties of the prepared films were analyzed using X-ray diffraction, Raman spectrum, scanning electron microscopy, EDAX, UV-visible spectrum. X-ray diffraction study revealed the growth of polycrystalline face-centered cubic PbS thin films without any impurities. Increase of doping concentration resulted in a decrease in peak intensity indicating the degradation of crystalline quality. The Raman peaks observed at 190, 240 and 464 nm justified the formation of PbS phase. Surface morphology of the films showed dopant concentration dependent compact and uniform distribution of grains on substrate. EDAX studies legitimized the existence of Pb, S, and Pr in the prepared films. Energy band gap values of the films were gradually increased from 2.18 to 2.69 eV for the increase of doping concentration from 0 to 5 wt%. The prepared films exhibited increased currents for the increase of doping concentration with reasonable photosensing effect inI-Vmeasurements. [GRAPHICS] .