Preparation of perovskite CsPb(Br_{: X} I_{1- x} )₃quantum dots at room temperature

Here, we propose a method for preparing red perovskite CsPb(BrxI1-x)3 quantum dots (QDs) at room temperature. The PL emission peak of the QDs is close to 650 nm, and the full width at half maximum reaches 61 nm. The red CsPb(BrxI1-x)3 QDs with higher water stability are obtained successfully at room temperature by adjusting the proportion of halogen elements and incorporating polystyrene. At the same time, the red QDs are combined with a blue light-emitting diode to prepare a white light-emitting device (WLED). Compared with the WLED based on the Ce-doped Yttrium Aluminum Garnet (YAG:Ce) phosphor alone, the new WLED based on QDs exhibits a reduced correlated color temperature of 2976 K, while achieving a lumen efficiency of 55.3 lm W-1, which provides a feasible solution for future research on light-emitting diodes (LEDs).