Phase–Change Liquid Encapsulated Quantum Dot Color Conversion Film for Wide Color Gamut LCDs

Abstract Quantum dot (QD) color conversion films encapsulated with high barrier films are being applied to wide color gamut liquid crystal displays (LCDs). However, besides the expensive cost of barrier films, the aging of QD films under high temperature and high‐intensity blue light remains unresolved. Here, a QD color conversion film is developed using phase‐change liquid encapsulation suitable for roll‐to‐roll film fabrication. In this method, the QDs are encapsulated in the phase‐change material octadecane, which switches between solid and liquid states in response to temperature changes corresponding to standby and operation of the display, respectively. This process endows the self‐healing of QD ligands (liquid state) and effectively increases the lifespan of QDs under ultraviolet (UV) light. This novel phase‐change liquid encapsulation method significantly improves the UV light resistance and long‐term stability of QD color conversion films compared to conventional solid‐state encapsulation. Under conditions of 60 °C, 90% humidity, and 40 mW cm⁻² blue LED backlighting, the phase‐change liquid encapsulated QD color conversion film maintains less than 10% brightness degradation for 680 h. This phase‐change liquid encapsulation technology opens new possibilities for manufacturing more durable QD color conversion films.