Facile synthesis of thermally stable CsPbBr3 perovskite quantum dot inorganic SiO2 composites and their application to white light-emitting diodes with wide color gamut

In this study, highly efficient green-to-red-emitting CsPbBr3-zIz perovskite quantum dots (PQDs) with high color purity are synthesized and a facile route for the formation of PQD-inorganic SiO2 composites is proposed. To improve thermal and water stability of the PQDs, perhydropolysilazane (PHPS)-derived SiO2 composites are prepared. The CsPbBr3-SiO2 composites exhibit highly enhanced thermal stability and water stability. The green emitting CsPbBr3-SiO2 composites and red-emitting CsPbBr1.2I1.8 PQDs are coated on blue light-emitting diodes (LEDs) and the fabricated green and red LEDs show high color purities of 95.1 and 99.5%, respectively. Finally, the white LED is fabricated by combining a blue LED with CsPbBr3-SiO2 composites and CsPbBr1.2I1.8 PQDs. The fabricated white LED shows bright natural white light (luminous efficacy = 35.4 linW(-1), correlated color temperature = 5623 K) with excellent color reproducibility due to wide color gamut (127% National Television System Committee color space).