Ultra Stable Quantum Dot Composite Film in Severe Environment.

Semiconductor quantum dots (QDs) have attracted extensive attention due to their remarkable optical and electrical characteristics. While the practical application of quantum dots and further the quantum dot composite films have greatly been hindered mainly owing to their essential drawbacks of extreme unstability under the oxygen and water environments. Herein, one simple method has been employed to enhance enormously the stability of CdxZn1-xSeyS1-y quantum dot composite film by a combination of CdxZn1-xSeyS1-y quantum dots and particular polyvinylidene Fluoride (PVDF), which is characteristic of closely arranged molecular chains and strong hydrogen bonds. There are many particular advantages in the quantum dot/PVDF composite films such as easy process, low cost, large area fabrication, and especially extreme stability even in the boiling water for more than 240 minutes. By employing the K2SiF6:Mn4+ as red phosphor, a prototype white LED with a color coordinates of (0.3307, 0.3387), Tc of 5568K, color gamut 112.1NTSC(1931)% at 20mA has been fabricated, and there is little variation under different excitation currents, indicating that the quantum dot/PVDF composite films fabricated by this simple blade-coating process make them ideal candidates for LCD backlight utilization via assembling white LED on a large scale owing to its ultra-high stability under the severe environment.