Encapsulating all-inorganic perovskite quantum dots into mesoporous metal organic frameworks with significantly enhanced stability for optoelectronic applications

Abstract

CsPbX3 (X = Cl, Br, and I) perovskite quantum dots (PeQDs) possess outstanding optical properties. However, the poor stability hinders the application of CsPbX3 PeQDs. Here we report a new strategy to enhance the stability of the PeQDs by embedding CsPbX3 PeQDs into the mesostructure zinc-based metal organic framework (MOF-5) crystals. First, the pore structure of MOF-5 crystals is expanded to mesopores by using templating agents cetyltrimethylammonium bromide and 1,3,5-trimethylbenzene. And then, the CsPbX3/MOF-5 composites are obtained by the physical mixing of CsPbX3 PeQDs with the mesoporous MOF-5 crystals in solution. The mesoporous structured MOF-5 crystals worked as an excellent dispersion medium to endow CsPbX3 PeQDs with improved stability (thermal-stability, photo-stability and long-term stability) and the property against anion exchange. Using CsPbX3/MOF-5 composites, a warm white LED is obtained with the color temperature of 3607 K and a wide color gamut (124% of National Television Standards Committee). This study proposes a new strategy to improve the stability of PeQDs, which eliminates the obstacles to the applications of PeQDs.