Perovskite-on-polymer microspheres for optimized solid state lighting

Remote downconverters such as phosphors or quantum dots that are physically separated from the blue light-emitting diode (LED) chips can strongly enhance the luminescence efficiency of solid-state lighting (SSL) and liquid-crystal displays (LCDs) because of their reduced light reabsorption. However, the high cost of traditional remote downconverters has limited their wide adoptions in these applications. Herein, we report a one-step, general synthesis method that can convert commercial light-diffusing polymer microspheres into highly luminescent perovskite-based downconverters at an extremely low cost. Involving a quick antisolvent-induced heterogeneous nucleation, our method creates well-dispersed perovskite nanoparticles anchored onto polymer microspheres and the whole process takes only several seconds at room temperature without any complex experimental setups. Significantly, the as-synthesized perovskite-on-polymer microspheres offer widely tunable, highly saturated colors with light-diffusing capability. The pure green-emitting CsPbBr3 manifests a high PL quantum yield of 70.6% and superior stability in water is also demonstrated. With these very saturated colors, we propose two configurations of integrating these microspheres into SSL systems. Further optimizations demonstrate that highly efficient, excellent color-rendering, and circadian lighting can be achieved. Thus, these luminescent microspheres hold great promise to be adopted as a low-cost, high-quality replacement for the traditional, expensive remote downconverters in SSL, LCDs and beyond.