Overcoming the poor performance of n-CdS/p-SnS solar cells by plasmonic effect of gold and silver nanoparticles

Abstract

It is known that one of the biggest problems in CdS/SnS solar cells is the efficiency deterioration, which hinders their wider use in application fields. Consequently, in this research, we manipulated the poor photovoltaic performance of CdS/SnS solar cells by the plasmonic effect of silver and gold nanoparticles of particle size of about 7.1 ± 1.4 nm, and 10.01 ± 2.2 nm, respectively. The structural and morphological properties of each layer of the CdS/SnS heterojunction are inspected individually and in a bilayer form with and without nanoparticles (NPs) decoration. The EDAX analysis and surface roughness analysis are evaluated in detail. Furthermore, the measured optical absorption and reflection profile witnessed significant enhancements where the absorption is increased by 235.9% and 835.6% at 550 nm by Au-NPs and Ag-NPs decoration, respectively. The electrical characteristics of the engineered CdS/SnS heterojunction are tested under dark and different irradiances (20−100) mW/cm2. The decoration by the plasmonic nanoparticles induced marvelous improvements in the Voc and Jsc values. Excitingly, the Au-NPs improved the poor efficiency of the virgin CdS/SnS solar cell from (0.022–0.066) % by one order of magnitude to be in the range (0.436–0.51) %, while Ag-NPs decorated cell achieved efficiency in the range (2.507–4.363) %. This new record in CdS/SnS efficiencies is explained in terms of the heterojunction type transformation using the calculated band offsets depending on the resulted values of valance band maximum of CdS and SnS and the energy difference of core levels in the heterojunction form using the photoelectron spectroscopy results.