High optical modulation efficiency in perovskite CsPbI3/Br3 by ionic liquid ionization

An effective method to improve optical properties of perovskite CsPbI3/Br3 is a long-term goal pursued by researchers, such as incorporating, mechanism changing and structure optimizing. However, two significant problems still facing challenges including the complex fabrication process and low modulation efficiency. To contribute these, a method of ionic liquid modulation with respect to the photoluminescence PL intensity and peak position was demonstrated. The micro-structure including the information of crystal and bond in MAPbBr3/I3 soaking in C8H11F3N2O2 and C7H13N2 ∙ BF4 was supported by x-ray diffraction XRD patterns and Raman spectrum. A cube-like shape and size distribution mostly in 600–950 nm was imaged by scanning electron microscope. Then, compared with CsPbI3 before soaking in Hall measurement, the carrier concentration was improved about 46.1%, the mobility and resistivity were lowered around 39.2% and 40.2%, respectively. The modulation of intensity and peak position were confirmed by PL spectrum at room temperature. The absorption enhancement in excited state absorbs range was proved by transient absorption. Finally, the mechanism for optical modulation in this paper was systematically explained. The research method proposed in this paper can simplify the research process and improve the optical properties of the materials at the same time.