Low-cost Preparation and Photoelectric Property Study of PbSe Nanocrystalline Films

PbSe nanocrystalline films were deposited on glass substrates by chemical bath using the Pb(Ac)(2) solution and Na2SeSO3 solution as the reactants. Effect of the concentration of complexing agent ([OH-]) in the chemical bath on the crystal structure, morphology and electric-optical property of the film were investigated. The results indicate that crystal size of the film is about 10nm which is correlated with the complexing agent concentration. With low concentration of [OH-], the film is uniform and compact, whereas it becomes loose and discontinuous with high concentration of [OH-]. Optical transmission spectra show a blue shift of the absorption edge from 5 mu m to 1 mu m in the as-grown films, and the absorption edge moves to longer wavelength after annealing at 300 degrees C. The as-grown film shows a huge sheet resistant (>10G Omega), and the sheet resistant obviously decrease to 10k Omega similar to 100M Omega after annealing in air and in oxygen. Electro-optical performance is studied by measuring the current vs time (i - t) curve at a signal of light pulse. The i - t curves indicate an obvious photoelectrical response in nanocrystalline films at the presence of light. The film annealed in air has a slow-electro-optical performance, whereas the film annealed in oxygen has a fast response.