Modification of physicochemical and electrical characteristics of lead sulfide (PbS) nanoparticles (NPs) by manganese (Mn) doping for electronic device and applications

In the present study, Pb_1−xMn_xS (0, 0.04, and 0.06) nanoparticles (NPs) were prepared by chemical co-precipitation process. The effects of Mn doping on the structural, morphological, vibrational, optical, and electrical characteristics of the PbS nanoparticles were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, UV–Vis spectroscopy, and I–V characteristics respectively. XRD patterns confirm the face-centered cubic (fcc) structure without impurity phases. The average crystalline size, unit cell constant, and porosity were found in the ranges of 11.93–14.33 nm, 5.7250–5.6888 Å, and 4.80–2.35%, respectively. SEM analysis revealed the flower-like, stone-like, and rode-like shapes of the Pb_1−xMn_xS (0, 0.04, and 0.06) nanoparticles. SEM images show that the PbS with Mn doping has flower, stone, and rod-like shapes for the samples doped with 0%, 4%, and 6%, respectively, Raman spectra depicted that the 6% Mn-doped PbS nanoparticles have stronger, and sharper peak intensity and bands as compared to PbS nanoparticles doped with 0 and 4%. The energy band gap decreased from 1.48 to 1.42 eV by increasing Mn concentration as compared to that of pure PbS nanoparticles. The electrical studies show that the increase in Mn-doping contents enhanced the electrical characteristics of the PbS nanoparticles without any structural distortions. The resistivity of the Pb_1-xMn_xS (0, 0.04, and 0.06) nanoparticles reduced from 1.3 × 10⁶ to 2.1 × 10³ Ω cm and conductivity increased from 7.69 × 10⁻⁷ to 4.76 × 10⁻⁴ Ʊ cm⁻¹ with Mn content. Due to extraordinary characteristics and narrow band gaps, pure PbS and Mn-doped PbS nanoparticles are suitable for electronic devices operated at low temperatures.