Transparent and flexible cellulose based luminescent film for multifunctional applications

Metal halide perovskite quantum dots (QDs) film shows significant potential in flexible optoelectronics, including applications in lighting, displays, wearable devices and non-planar X-ray imaging. However, developing highly luminescent, durable, and mechanical flexible film for practical use remains a challenge. In this study, we introduce a low-cost, environmentally friendly, biomass material - mixed cellulose esters (MCE) - as a novel encapsulation matrix. The CsPbBr₃@MCE composite luminescent film was fabricated using a simple in-situ growth strategy, ensuring uniform distribution of QDs within the matrix. The chemical bond anchoring between MCE and CsPbBr₃ QDs, combined with the effective isolation provided by in-situ encapsulation, resulted in exceptional luminescence properties, including a high photoluminescence quantum yield (PLQY = 67.73 %) and excellent color purity. Additionally, the film demonstrated enhanced stability against environmental, thermal, ultraviolet, and high-humidity stresses, thanks to the protective encapsulation of MCE. It also exhibited remarkable mechanical flexibility, transparency, the capability for large-area production. These findings suggest that the CsPbBr₃@MCE composite holds great promise for various applications, including light-emitting diodes, flexible pattern display, hazardous chemical identification, information encryption, and anti-counterfeiting technologies.