Dielectric Constant Consideration of Plasmonic Nanostructures for Enhanced Multi-Junction Solar Cell

The inherent loss issues of existing surface plasmon materials significantly limit their applications in various optical and optoelectronic devices. In particular, substantial plasmon absorption and backscattering remain major challenges to achieving enhancements in high-efficiency multi-junction solar cells. In this study, we abstracted the dielectric constants of plasmonic materials and investigated the enhancement mechanisms of general plasmonic materials in photovoltaic devices. By optimizing the dielectric constant, optical loss can be effectively mitigated, and ideal materials with weak dispersion could enhance the broadband spectral response and current density of triple-junction GaAs solar cells. Additionally, a comparative analysis of actual plasmonic materials demonstrated that silver, gold, and aluminum align with the optimized enhancement parameters within specific spectral ranges. These results provide valuable guidance for the selection and design of advanced plasmonic materials tailored to future photovoltaic applications.