Facile synthesis of ytterbium doped cesium lead halide perovskite powder

Abstract

Ytterbium-doped perovskites have been demonstrated as a suitable system for fabricating quantum-cutting materials, which show promising potential for enhancing solar cell efficiency and various other optoelectronic applications. Cesium lead halide perovskites (CLHPs) strongly absorb high energy photons, and their energy can be transferred to ytterbium ions, which subsequently emit two photons of approximately two times lower energy. Typically, CLHPs in the form of nanoparticles or thin spin coated films are used for this purpose. In this paper, we present an alternative mechanosynthesis-based technique for the fabrication of quantum-cutting materials. We demonstrate the formation of CLHP powders doped with ytterbium using dry and wet mechanosynthesis techniques, followed by a comprehensive examination of their structural and optical properties. Both synthesis methods allow doping of perovskites with ytterbium ions by incorporating them into the perovskite lattice substituting lead ions. We show that there is no essential difference between the powders prepared using both techniques. The ytterbium doped into the perovskite effectively quenches the excitonic emission and enables ytterbium photoluminescence efficiencies above 100%, with the champion PLQY of the sonicated CsYb_0.05Pb_0.925Cl₃ powder embedded into polymer matrix reaching 160%.