Toward 90 μm Superthin Transparent Wood Film Impregnated with Quantum Dots for Color-Converting Materials

Flexible quantum dots (QDs) photoluminescent films are emerging as a new generation of light-emitting materials. Such films are commonly fabricated by dispersing QDs on flexible plastic films or impregnating them into porous layers due to the vulnerability of QDs to water and oxygen. However, these substrates are mainly made from petroleum-based materials, causing serious environmental issues. Here, for the first time, we propose a top-down strategy to prepare QDs photoluminescence films from a superthin, superflexible, and transparent wood film. The top-down method involved several steps. First, a wood film was produced using horizontal veneer slicing technology from natural wood. Second, the wood film underwent a delignification process and the impregnation of QDs along with epoxy resin. The resulting superthin and transparent photoluminescent QDs wood film had a record thinness of 90 μm, a record curvature radius of 1.3 mm, a high transmittance of approximately 90%, and a high fluorescence intensity. Further, we applied the QDs superthin film to fabricate color-converting films to emit red, blue, and green lights under ultraviolet radiation or excited by blue light emitting diodes. In addition, the film could also resist water, alkaline solutions, salt solutions, and organic solvents for 10 days without losing light-emitting abilities. This simple and fast method provides an environmentally sustainable solution for the design of green, flexible photoelectric devices.