Stable White Light-Emitting Biocomposite Films

The demonstration of reliable and stable white light-emitting diodes (LEDs) is one of the main technological challenges of the LED industry. This is usually accomplished by incorporation of light-emitting rare-earth elements (REEs) compounds within an external polymeric coating of a blue LED allowing the generation of white light. However, due to both environmental and cost issues, the development of low-cost REE-free coatings, which exhibit competitive performance compared to conventional white LED is of great importance. In this work, the formation of an REE-free white LED coating is demonstrated. This biocomposite material, composed of biological (crystalline nanocellulose and porcine gastric mucin) and organic (light-emitting dyes) compounds, exhibits excellent optical and mechanical properties as well as resistance to heat, humidity, and UV radiation. The coating is further used to demonstrate a working white LED by incorporating it within a commercial blue LED.