Computational study of “sandwich” configuration of plasmonic nanoparticles to enhance the optoelectronic performance of thin-film solar cells

This study uses Finite-Difference Time Domain (FDTD) simulations to investigate the possibility of using a “sandwich” nanoparticle configuration where a core (metal)-shell (dielectric) nanoparticle (NP) is embedded within the silicon absorbing substrate of a thin-film solar cell and is coupled with a silver nanoparticle placed on the top of the substrate to cumulatively increase the opto-electronic performance of the solar cells. The core-shell nanoparticle (Ag-SiO
₂
core-shell NP) inserted inside the semiconductor absorbing layer contained an outer shell layer made of SiO
₂
that covered the inner silver nanoparticle core to allow the creation of conditions suitable for surface plasmon resonance (SPR) as the SPR requires a metal-dielectric interface. The solar cells coupled to the “sandwich” configuration of Ag NP and Ag-SiO
₂
core-shell NP exhibited superior response when compared to a bare silicon substrate and with the silicon substrate coupled to a Ag-NP alone or Ag-SiO
₂
core-shell nanoparticle alone, respectively, based on different performance parameters such as optical absorption enhancement, short-circuit current density (J
_sc
), open-circuit voltage (V
_oc
), optical near-field enhancement, fill factor, output power generated and efficiency. Of the different configurations studied, the optimal results were achieved for the case of a AgNP with 160nm diameter placed on the top of the Silicon substrate and Ag-SiO
₂
core-shell nanoparticle with 100nm diameter of the silver core and 5nm thick silica shell embedded inside the Si substrate at a height of 5nm below the Si substrate top surface. The results of this study indicate that such plasmonic “sandwich” configurations of Ag-SiO
₂
core-shell NP together with Ag NP can potentially be used to significantly boost the opto-electronic performance of commercially available thin-film solar cells.