Perovskite Nanocrystals for Down Conversion Displays and AR/VR Application

Colloidal perovskites nanocrystals (PeNCs) have been proven to possess high color purity (FWHM ~ 20 nm), high photoluminescence quantum yield (PLQY) and low-cost solution processability, making them promising candidates for the next generation light emitters. However, poor stability and the potential toxicity issues arising from lead leakage have hindered the commercialization of PeNCs. Furthermore, light-induced halide segregation limits the spectral stability of red and blue perovskite nano crystals, restricting their spectral tunability.<br/>Here, first of all, we have developed ultra-stable and bright PeNCs by constructing a multi-layer structure. The multi-layer structure improved aging stability under 60 oC and 90% relative humidity condition and the photostability. Furthermore, this structure successfully prevents the leakage of lead, significantly reducing the toxicity of the nanocrystal film. Secondly, we have developed polymer matrix to improve stability of PeNC film. The polymer matrix successfully prevents degradation of PeNC by external condition and halide, leading to stable PeNC down conversion films with long lifetime under 60 oC and 90% relative humidity condition and under high flux (100 mW/cm2). With efficient and stable PeNC down conversion film, we successfully demonstrated a 28-inch monitor and a 10.1-inch tablet that surpasses existing products in terms of vivid images, achieving Rec. 2020 over 95%. Our work sheds great light on the potential that PeNCs can be commercialized in the near future.