Flexible polyphosphazene nanocomposite films: Enhancing stability and luminescence of CsPbBr3 perovskite nanocrystals

Polyphosphazene with phenoxy or 4-ester phenoxy as pendent groups are demonstrated as both ligands and host matrices for CsPbBr3 perovskite nanocrystals (NCs). These polymers produced flexible nanocomposite films with excellent NCs dispersion, optical transparency and stability in various extreme conditions. Both films remained stable even after 30 days of air storage. CsPbBr3/poly [bis-(phenoxy phosphazene)] (PBPP) delivered better air and light stability, and CsPbBr3/ poly [bis-(4-ester phenoxy) phosphazene] (PBEPP) exhibited superior water and heat resistance. CsPbBr3/PBEPP showed a greater increase in fluorescence intensity under 365 nm UV light and demonstrated a 10% luminescence increase after 96 h of water immersion and even at high temperature (150 °C). These findings thus provide new insight into flexible luminescent CsPbBr3 films with high stability in optoelectronic applications.