Enhanced photon harvesting by embedding cost-effective polystyrene microspheres as light scatterers in the perovskite photodetector

Solution processed perovskite photodetectors have attracted extensive interest in recent years. For future commercialization, highly efficient and stable devices need to be realized. Herein, we demonstrate that by introducing low-cost polystyrene microspheres as light scattering media in a p–i–n perovskite photodetector, enhanced photoelectric conversion rate can be obtained. Based on Mie scattering theory, a theoretical design was firstly executed to calculate the optimized microsphere size and then applied to the fabrication of the detector. After embedding microspheres, the high photocurrent and responsivity under 760 nm incident light illumination (light intensity P = 1.0 mW cm−2) reached 19.05 μA and 0.32 A W−1, respectively, which were nearly twice enhancements in comparison with the pristine device. Similarly, the improvement of detector performance response to 530 nm incident light was observed for the polystyrene microsphere embedded device. The maximum responsivity up to 0.45 A W−1 (P = 1.0 mW cm−2) and on/off ratio up to 104 were achieved. This work provides an effective design and implementation strategy to improve responsivity to specific light illumination for perovskite photodetectors.