Structural, electrical, and optoelectrical characterization of PbS nanoparticles

Lead sulfide (PbS) nanoparticles show the potential to establish as photoelectrical materials for photodetectors for the next generation. The excellent electrical and optical properties including polarity, carrier mobility, carrier concentration, and conductivity are widely investigated using thin films of PbS nanoparticles and it is ascribed to the strong quantum confinement effects. The various optoelectronic devices are fabricated with PbS nanoparticles as versatile building blocks. The transport properties of thin films of these PbS nanoparticles depend on the size, shape, and stoichiometry. In the present study, chains like PbS, spherical PbS, and cubic PbS nanoparticles are grown by a cost-effective chemical reduction route. The effect of the quantity of reducing agents (NaBH4) was investigated on the morphology and size of the products. Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD) patterns show the formation of PbS nanoparticles. The average particle size is 8 nm, 15 nm, and 23 nm for Spherical, Cubic, and Chain PbS nanoparticles. EDS analysis also confirms the XRD results. Quantum confinement is achieved for different shaped PbS nanoparticles and hence thereby the bandgap is increased. The electrical parameter like conductivity, hole concentration, and hole mobility is determined from conductivity and Hall experiment data. Photoconductivity for all PbS samples was performed at room temperature under the illumination of 50 mW/cm(2). Photosensitivity and Detectiviy are calculated for different shaped PbS nanoparticles.