Absorption Depth Profile of Silicon Substrate in the Presence of Copper Nanoparticles: A Study on Simulation and Fabrication Thereof

Copper nanoparticles have attracted interest in the field of solar cells due to their potential for improving light absorption, plasmonic effects, cost-effectiveness, non-toxicity, and simplicity of production and integration. In this context, simulative prediction of such system facilitates efficient device fabrication. In this work, finite-difference time-domain (FDTD) analysis was carried out to understand the influence of copper nanoparticles within silicon (Si) substrate. An FDTD model, "Copper nanoparticles array as 3×3 on c-Si slab" was developed and absorption depth profiles were extracted at several incident wavelengths of solar spectrum for different interparticle gaps of copper nanoparticle array. It was noted that absorption distribution within Si substrate depended on incident wavelengths of solar spectrum as well as distribution of copper nanoparticles. To realize the results obtained in FDTD simulation, a simple strategy was devised to fabricate copper nanoparticulate using sputtering technique. High resolution field emission scanning electron microscopic (FESEM) images revealed that as-fabricated copper nanoparticles were in the range of 80-100 nm in diameter. FESEM-aided energy dispersion spectroscopy confirmed the elemental composition of the copper nanoparticulate.