High transparency pixelated color converter based on luminescent europium(III) complex

Transparent display screen is an innovative display technology, which is different from traditional displays and can achieve a combination of transparency and image display. Although OLED and Micro-LED have been used for high pixel transparent displays, the cost and color pixelization remain challenges. In this work, we attempt a new approach based on luminescent rare-earth ion complex, which is a highly thermally stable ternary organic complex of europium(III) containing naphthalene pyridine. Combining with lithography technology, we achieve a high transparency pixelated color converter. This lead- and cadmium-free europium(III) composite material exhibits excellent optical properties, with a FWHM of 12.5 nm, which is much narrower than traditional lead-/cadmium-free quantum dots (such as InP) and even better than cadmium based. In our current process, the pattern size can be reduced to 10 μm, and a large-area of high transparency color convertion film (> 88% at 450 nm) can be obtained on a flexible PET substrate. Our work provides a new solution for the implementation of lead- and cadmium-free transparent displays.