Stretchable Primary-Blue Color-Conversion Layer Enabled by In Situ Fabricated Perovskite Nanocrystals Embedded in an Organic Matrix

While the use of red, green, and blue color-conversion layers (CCLs) with backlighting ultraviolet (UV) light-emitting diodes enhances display uniformity and streamlines the fabrication process in the display industry, research on blue CCLs is still insufficient, particularly in the primary-blue region. In order to accomplish the Rec.2020 color standard, primary-blue CCL is necessary to be further explored. This work reports a stretchable primary-blue CCL enabled by <i>in-situ</i> fabrication of perovskite nanocrystals (NCs). The films exhibit high-stretchability characteristics, emit primary-blue light (~460 nm), and maintain steady photoluminescence (PL) under UV irradiation. By introducing fluorinated arylammonium salts, controlled quantum confinement and dielectric confinement effects adjust the energy transfer among diverse perovskite phases. Perovskite NCs are embedded in an organic matrix composed of ammonium salts, which prevent degradation under mechanical stress. Additionally, we suggest a novel set of scientific guidance rules related to the crucial factors that influence the nucleation and crystallization kinetics of <i>in-situ</i> fabrication of perovskite NCs. Consequently, the stretchable blue CCL emits spectrally stable PL at primary-blue region (~460 nm) under high tensile strain (&gt;200%) and prolonged UV irradiation.