Broad-band absorption enhancement in lower absorption coefficient region in CZTS solar cells with embedded aluminum nanoparticles into absorber layer
Finite-difference-time-domain (FDTD) electromagnetic calculations are performed fora CZTS solar cell with embedded 100 nm aluminum (Al) nanoparticles (NPs) in the absorber layer. We predict significantly enhanced absorption for wavelengths where absorption is intrinsically low. Overall, over 17% enhancementis predicted in absorbed photon flux and (maximum attainable) current density below the absorber band gap. These are due to near-field enhancement by localized surface plasmon resonance (LSPR) and far-field enhancement by scattering from Al NPs. The increase in absorbed photon flux is explained through Mie scattering calculations in Lumerical FDTD.