Thermal Polymerization Synthesis of CsPbBr3 Perovskite-Quantum-dots@copolymer Composite: Towards Long-Term Stability and Optical Phosphor Application

•The CsPbBr3 PQDs composite was synthesized via a modified one-pot thermal polymerization strategy.•The CsPbBr3 PQDs composite with a record high PL-QY of 90% was obtained.•The CsPbBr3 PQDs composite shows an excellent long-term stability.•The embedded PQDs could be easily released from the copolymer matrix.•A white LED based on this composite exhibits a high luminous efficiency of 90 lm/W.