Flexible and foldable films of wCDs/BNNS-OH/PVA white light composite with high stability and heat dissipation

Abstract

Recently, carbon dots (CDs) have gained much attention in optoelectronic fields on account of their superior optical and environmentally friendly properties. Nevertheless, aggregation-induced quenching (AIQ) effect of solid-state CDs and thermal quenching caused by high temperatures severely hinders their further development. Herein, a novel wCDs/BNNS-OH hybrid nanostructure was synthesized by combining blue CDs (bCDs) and yellow CDs (yCDs) to the hydroxylated boron nitride nanosheets (BNNS–OH) surface. The uniform dispersion of CDs in BNNS-OH effectively alleviates the undesirable AIQ effect, and enables CDs/BNNS-OH composites to have color-tunable fluorescence characteristics. The wCDs/BNNS-OH/PVA composite film was obtained by encapsulating wCDs/BNNS-OH into polyvinyl alcohol (PVA). The film exhibits excellent luminescence stability in the air, ultraviolet light, water, and high-temperature environment. Meanwhile, since wCDs/BNNS-OH establishes an effective heat transfer channel in the PVA matrix, the working temperature of CDs in the wCDs/BNNS-OH/PVA film is greatly reduced. Moreover, the prepared wCDs/BNNS-OH/PVA film is flexible enough to retain the photoluminescence intensity unchanged after thousands of bending cycles. This high stability and heat dissipation wCDs/BNNS-OH/PVA composite film will facilitate the application of CDs in flexible and foldable lighting devices.