Synthesis and properties of lead selenide nanocrystal solids

We present results of our investigation of the synthesis, structural properties and electrical transport properties of lead selenide (PbSe) nanoparticle-derived solids. Stable colloidal solutions containing crystalline PbSe particles with sizes on the order of 5-10 nm were synthesized using an organometallic lyothermal growth method in high-temperature organic solvents (100∼200°C). The nanoparticle powders have been characterized by X-ray scattering (WAXS/SAXS), electron microscopy and optical absorption. Thin films were formed by controlled precipitation of the nanoparticles from solution onto insulating substrates. Electrical resistance (R) and Seebeck coefficient (S) for conductive PbSe films from different annealing conditions were studied and compared. We were able to obtain conductive PbSe films from colloids by low temperature annealing which did not disturb the nanoparticle self-assembly.