Preparation of ultra-stable and environmentally friendly CsPbBr3@ZrO2/PS composite films for white light-emitting diodes

Abstract

The working stability of perovskite light-emitting diodes (LEDs) has become an urgent bottleneck to be solved in the process of commercialization. Although lead halide perovskite CsPbX₃ (X = Br, I, Cl) quantum dots (QDs) are considered rising stars in the lighting market owing to their excellent optoelectronic properties, they suffer from fluorescence quenching under thermal conditions. Unfortunately, the surfaces of electronic devices inevitably warm up under long-term energization, which is extremely detrimental to the appropriate functioning of CsPbX₃ QDs. Based on the above discussion, the relationship function between the energization time and surface temperature of electronic devices was analyzed, after which a strategy for the preparation of dual-encapsulating perovskites using organic (polystyrene (PS)) and inorganic (ZrO₂) materials was proposed, and the change in optical stability before and after encapsulation was investigated. The results show that the thermal stability of CsPbBr₃@ZrO₂/PS composite films (CFs) after the dual encapsulation was remarkably enhanced, and the assembled white LEDs still retain the initial emission intensity under prolonged high-power operation. In addition, the double encapsulation layer completely suppresses the ion leakage in CsPbBr₃ and avoids damage to the ecosystem. It can be seen that this encapsulation strategy was capable of imparting excellent working stability to the perovskite material, which would clear the obstacles to commercial conversion.