Enhanced luminescence of self-crystallized Cs4PbBr6 quantum dots via regulating glass ceramic network structure

Abstract

The most used method to obtain Cs4PbBr6 quantum dots (QDs) in glass is heat treatment, but the more energy-efficient method of self-crystallization is seldom explored. In this work, Cs4PbBr6 QDs are obtained in glass matrix through self-crystallization method. The results elucidate that with the increase of Na2O, glass network structure transforms from three-dimensional (3D) framework structure to two dimensional (2D) layered structure and phase separation process of glass is aggravated. The looser network structure facilitates atoms rearrangement, and the presence of phase interface reduces activation energy of nucleation. Both of the two aspects can promote the self-crystallization of Cs4PbBr6 QDs. Importantly, the PLQY of PG3 is 81.24 %, which is much higher than the heat treated one (CG3:11.89 %). Finally, a green backlit light-emitting diode (LED) with high color purity of 96.1 % and white light-emitting diode (WLED) with color coordinate of (0.3212, 0.3315) are fabricated. Our work puts forward a new perspective to investigate QDs glass ceramic and brings QDs glass ceramic significant prospect in the optoelectronic applications.