Enhancing Light Absorption in Perovskite Solar Cells Using Au@Al2O3 Core–Shell Nanostructures: An FDTD Simulation Study

Adding plasmonic nanostructures to perovskite solar cells (PSCs) can boost light absorption, but often at the cost of new electronic losses. Based on 3D FDTD simulations, this study demonstrates how Au@Al2O3 core-shell nanostructures can overcome this fundamental trade-off through a dual function of the Al2O3 shell, namely its moderate refractive index and excellent passivating properties. In addition, the geometry of Au@Al2O3 core–shell nanostructure is optimized to produce a maximum short-circuit current density (Jsc) of 25 mA cm−2. The simulations provide mechanism-level design rules that link dielectric choice and geometry to near-field localization and far-field coupling in perovskite absorbers. An experimentally testable parameter window is reported rather than device-level performance claims, with explicit discussion of energy partitioning and stability caveats associated with plasmonic loss in Au and interfacial chemistry.