Synthesis, morphological, optical and structural properties of PbSSe2− nanocrystals

Herein Se2−-doped PbS thin films obtained by using the green chemical bath approach are reported. Morphological, optical and structural properties were investigated by atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and optical absorption. Three impurity levels were prepared by changing the relative volume of the solution containing Se2− ions in the PbS growing solution. XRD showed growth of all films with the zinc-blende phase. Changes in the grain size (∼27-14 nm) and band gap energy (∼1.4-2.24 eV) were observed. The absorbance in doped films, showing excitonic peaks are due to higher energy transitions from 1Se →1Sh. Gibbs energy calculation for the Se2− doping PbS process was also investigated.