Hydraulic shear-induced rapid mass production of CsPbBr₃/Cs₄PbBr₆ perovskite composites

A CsPbBr₃/Cs₄PbBr₆ perovskite composite, which exhibits highly efficient pure green luminescence and better long-term stability than CsPbBr₃ nanocrystals, has emerged for wide color gamut displays and various optoelectronic applications. While many reports have been made on the optoelectronic properties of perovskite materials, the study of the rapid mass synthesis of this material remains challenging. In addition, more case studies are still needed to optimize the conditions such as the differences in raw materials or addition of ligands, and to clarify these changes. Here, a new synthesis strategy is reported that enables rapid mass synthesis of green-emitting perovskite composites by forming ultrafine reverse microemulsions by hydraulic shear. Furthermore, in this synthesis method, the oleylamine (OLA)/oleic acid (OA) ratio plays an important role in the improvement of photoluminescence quantum yields (PLQYs), which is ascribed to the increase of luminescent CsPbBr₃ in the Cs₄PbBr₆ matrix. This high color purity green-emitting perovskite composite exhibits excellent optical properties of a high PLQY of 50.6%, an emission wavelength of 519 nm, and a narrow full-width at half-maximum of 22.4 nm