Suppressed phase segregation in CsPbIBr2 based PeLEC

In this work we describe some strategies to suppress phase segregation in perovskite light-emitting electrochemical cells based on mixed halide CsPbIBr₂ perovskite. Lead halide perovskites are widely used class materials used for  creating optoelectronic devices. However, appearing phase segregation causes peak separation on photo- and electro luminance spectra, which limit efficiency and color rendering of devices based on lead halide perovskite materials. Improving crystallinity of perovskite film by annealing temperature controlling can affect halide separation. Mn²⁺ doping was used to enhance materials stability of lead halide perovskite. Another strategy is crystal grains  passivation by polymers, i.e. polyethylene oxide and polyvinylidene fluoride, which reduce crystal defect density that cause phase segregation. All these strategies were applied in this work and demonstrate single peaks on photo-  and electro luminance spectra. Suggested solution of phase segregation problem allows to create more stable and effective CsPbIBr₂ based perovskite light-emitting electrochemical cells that work in red range of visible spectrum  (620-680 nm).