Effect of diphenylphosphine in the synthesis of PbSe nanoparticles

PbSe nanoparticles (NPs) were synthesized varying the amount of diphenylphosphine (DPP) added (0, 0.05 and 0.1 ml) to the selenium precursor (TOP-Se to 97%), with a reaction time of 15 minutes. Subsequently, the obtained PbSe NPs were characterized using transmission electron microscopy (TEM) to assess the effect of the variation of the DPP on their morphology, size, crystal structure and yield of the reaction. Increasing the amount of DPP in the reaction produced smaller nanoparticles, with better size distribution and increased the yield of the reaction. The optical properties were evaluated using UVVis-NIR spectroscopy, in order to obtain the first absorption peak of the NPs, and from this value calculate the energy band gap (Eg); which showed a correlation with the average size measured on each sample, as it has been reported on the literature. Additionally, this study settles the basis for a better understanding of the role of DPP in the synthesis of PbSe nanoparticles, and provides a guideline for proper selection of the ratio Pb/DPP used in the synthesis.