Water-Recycled Perovskite for White Light-Emitting Diodes

Organic–inorganic lead halide perovskites have attracted great interest because of their excellent optoelectronic property. The largest problem hindering the real application was degradation due to humidity. In this paper, we report an economic and environmentally friendly aqueous method for synthesizing the composite perovskite MAPbBr3@PbOHBr and further employing the product as a waterproof fluorescent material in underwater devices. The composite material has excellent photoluminescence (PL) with a quantum yield of about 58%. The PL intensity decreased by only 14% when it was maintained in ethanol for 100 days. Furthermore, the synthetic water-resistant material maintained a 71.6% initial PL intensity after five recycles in water with harsh conditions of ultrasonication, centrifugation, and drying. The white light-emitting devices were also fabricated using the composite material as phosphors on a 365 UV chip. This aqueous synthetic method gave a new inspiration in the high-quality water-resistant recycled fluorescent material preparation in the future.