A deep-dyeing strategy for ultra-stable, brightly luminescent perovskite-polymer composites

Abstract

To fulfill the requests of highly vivid colors in displays and customized spectra in solid-state lighting (SSL), a cost-effective approach to create color-tunable downconverters with narrow emission spectra is in demand. In this regard, perovskite nanocrystal downconverters have aroused great interest due to their narrow-band, tunable emission and easy manufacturing process. However, environmental instability is still the major concern of their commercialization, especially for red-emitting downconverters. Herein, built upon the previous successful development of a swelling–deswelling microencapsulation (SDM) method, we report a deep-dyeing strategy that can directly convert commercial solvent-resistant polymer matrices (e.g. polyethylene terephthalate (PET)) into polymer-protected deep-dyed perovskite polymer composites (DDPPCs) with outstanding color tunability, excellent pure color, and superior environmental stability. The MAPbBr₃-based DDPPCs manifest a high photoluminescent quantum yield of 77.9%. Moreover, they survived in water for over 3 years without visible degradation, their photoluminescence (PL) is reversible under a 140 °C heating–cooling cycle, and they maintained 87.6% of the original PL intensity after 10 hours of continuous blue laser excitation. More importantly, the as-synthesized CsPbBr_0.75I_2.25-based red DDPPCs also exhibit excellent water-, thermal-, and photo-stability. The deep-dyeing process is expected to achieve highly stable PPCs for next-generation displays, SSL or other applications.