A Building Brick Principle to Create Transparent Composite Films with Multicolor Emission and Self‐Healing Function

Abstract A cellulose paper is used impregnated with light‐emitting CdTe nanocrystals and carbon dots, and filled with a polyurethane to fabricate uniform transparent composite films with bright photoluminescence of red (R), green (G), and blue (B) (RGB) colors. A building brick‐like assembly method is introduced to realize RGB multicolor emission patterns from this composite material. By sectioning out individual pixels from monochrome‐emissive composite sheets, the advantage of the self‐healing properties of polyurethane is taken to arrange and weld them into a RGB patterned fabric by brief exposure to ethanol. This provides an approach to form single layer RGB light‐emitting pixels, such as potentially required in the display applications, without the use of any lithographic or etching processing. The method can utilize a wide range of different solution‐based kinds of light‐emitting materials.