Synthesis and study of thin films of (PbSe)100-xBix nanomaterials

Abstract

Melt quenching technique has been applied for the synthesis of (PbSe)100-xBix alloys and its thin films have been deposited on the glass substrate at 100 K by Thermal evaporation technique. The structural studies confirm the formation of a higher density of aggregated cubic QDs and the polycrystalline nature of the samples. As compared to other metal-doped PbSe materials, our Bi-doped samples exhibit a faster reduction in the size of the particles. This extraordinary behavior has a high influence on its optical band structure for better response and performance. Emission spectra exhibit an influential blue shift and peak broadening effect with the rise in x values, which give rise to a change in its energy band structure. These effects may be due to quantum size effects with various size distributions. The optical absorption suggests a direct bandgap of an increasing trend with x values of Bi. These trends are the information about the growing confinement effect with the reduction in the size of the particles, which results in the discrete density of states of high filling factor and the comparatively higher density of localized states. The width of the Urbach tail proposes a reducing trend with an increase in Bi content in the base sample. Such a trend might be occurring due to a reduction in band tails that gives rise to the broadening of the bandgap.