Broadband Light Absorption Enhancing in Thin Film Plasmonic Solar Cells Using Coupled Core Double Shell Nanoparticles

GaAs and InAs are common material choices for intermediate band solar cell implementation owing to lattice-matching and outstanding synthesizing quality. Core–shell NPs were introduced to increase the energy conversion efficiency of solar cells by enhancing and broadening scattering and absorption spectra. Core–shell-shell NPs are proposed as an alternative to enhance and broaden power absorption and light scattering spectra. The core is SiO2, and the internal and outer shells are Au and InAs. The core–shell-shell NPs provide platforms for hot electron transferring and plasmon resonance electron transferring processes and then increase the solar cell’s efficiency. For appropriate red-shifting and broadening of absorption and scattering spectra by the core–shell-shell NP, Au was preferred to Ag as the inner shell. The absorption and scattering red shifting above the GaAs energy gap are necessary to the plasmon resonance electron transferring and hot electron transferring, respectively. Changing Au and InAs thicknesses impacts the absorption and scattering cross-sections and broadening by LSPR coupling of the interfaces. With a 65-nm outer radius of the Au shell, the absorption cross-section peaked at 887-nm LSPR wavelength. Absorption broadening was realized from 650 to 1200 nm, owing to the LSPR coupling of the adjacent NPs and the internal interfaces of the NPs, nonlinear optical phenomena, and optical inelastic scatterings owing to NP presence in the GaAs substrate. The results do not show remarkable changes versus spaces among the NPs. Then, the LSPR coupling of the internal interfaces is the main factor. Therefore, the self-placing of the NPs would not impact on efficiency.