Photon Recycling-Driven Photodetection Enhancement in Ni(AcO)2-MAPbBr3 Nanocomposite Waveguides.

The reabsorption and reemision of photoluminescence (PL) photons, or photon recycled (PR) effect, has demonstrated outstanding benefits in solar cells or light-emitting diodes. Nevertheless, this process has been unexplored in photodetectors (PD) because reliably quantifying the photocurrent driven by PL photons is technically challenging. This work demonstrates the generation of a PR-driven photocurrent by incorporating a nickel acetate, Ni(AcO)2, nanocomposite containing MAPbBr3 (MA = methylammonium) nanocrystals (NCs) in planar waveguide structure integrating electrode contacts. The concentration of NCs in the matrix is optimized to enable efficient PL photon confinement and propagation over millimeter-scale distances until detected. Under modulated laser illumination, this mechanism enhances photocurrent by approximately 60%. Remarkably, under nanosecond pulsed excitation, the device generates an amplified spontaneous emission signal that is reabsorbed within the film, yielding a photocurrent peak of 0.8 mA per pulse. These findings demonstrate an effective strategy for enhancing the performance of MHP-based PDs.