Efficient Quasi-2D Perovskite Solar Cells Enabled by Gold Nanoparticles

Quasi-two-dimensional (quasi-2D) perovskites offer enhanced stability compared to conventional 3D analogs, but their applications in photovoltaics are hindered by low power conversion efficiencies (PCEs). The limited PCEs primarily originate from low short-circuit current density (JSC), caused by insufficient optical absorption, inefficient exciton dissociation and poor charge transport. Here, we find that the PCEs of quasi-2D perovskite solar cells (PSCs) can be significantly enhanced by incorporating gold nanoparticles (Au NPs) into quasi-2D perovskite layers. The optimized device achieves a champion PCE of 22.39%, ranking among the highest reported values for quasi-2D PSCs while retaining intrinsic stability. Our results demonstrate that Au NPs moderately promote light harvesting via plasmonic effects and increased perovskite layer thickness. More significantly, Au NPs substantially reduce exciton binding energy and enhance exciton dissociation probability, thereby facilitating charge separation and primarily driving device PCE improvement.