Plasmonic effect of spray-deposited Au nanoparticles on the performance of CSS CdS/CdTe solar cells

•Spray pyrolysis of HAuCl4 solution is reliable method for deposition of Au nanoparticles.•The Au nanoparticles grain sizes 30–100nm has been deposited on CdTe surface.•Enhanced CdTe/CdS solar cell efficiency by Au nanoparticles has been achieved. In order to improve the light trapping in CdTe thin-film solar cells, a coupling with plasmonic nanostructures is believed to increase the absorption as a result of the enhanced electric field and forward-scattering upon excitation of the surface plasmon resonance (SPR). The simulation studies suggest a technological feasibility of placing metallic nanoparticles on CdTe before back contacting. We have applied the chemical spray pyrolysis of different amounts of HAuCl4 ethanol solution to incorporate Au nanoparticles into CdTe and used this layer in CdS/CdTe solar cells. CdTe films show the SPR effect and an enhanced light absorption in the visible range of spectrum, whereas the CdS/CdTe solar cell have an improved conversion efficiency due to the presence of Au nanoparticles. The processes responsible for these advancements are discussed.