Effect of Temperature on Visible Photoluminescence of Thermally Annealed PbSe Nanocrystalline Films

The photoluminescence (PL) performance of thermally annealed PbSe nanocrystalline films has been investigated at different temperatures. The visible PL signals at 655 and 466 nm are observed for the as-prepared PbSe films, and the enhanced intensities of the two PL peaks are closely related to the optimized crystallization quality of PbSe nanoparticles after annealing at 50–150°C. However, as the annealing temperature is above 200°C, the severe surface damage of PbSe films induced by the oxide impurity phases and dislocation defects results in the reduction of the crystallinity of PbSe and the lower intensities of PL signals, which have been proved by means of X-ray diffraction (XRD) characterization. In addition, another emission peak at 429 nm is observed at the annealing temperature above 200°C owing to the appearance of the PbO impurity phase, and its intensity strongly depends on the content of the PbO impurity phase, whereas the PL intensity decreases above 350°C owing to the formation of PbSeO x .