White LED devices with nearly uniform space-color distribution through nanoparticle usage

With the rapid development of GaN-based light-emitting diodes(LEDs), high power white light-emitting diodes (wLEDs) have exhibited great potential to become general lighting sources. But they are suffering problems of color disharmony and low light extraction efficiency. In the present work, nearly uniform space-color distribution, around 30K, is obtained through the usage of TiO₂ NPs. This method is easy to be implemented. Normal dispenser machines can do. Further optimizing the concentration of TiO₂ NPs and fabrication technique, the correlated color temperature(CCT) deviation is expected to decrease to zero. Finally, aging tests prove that the usage of TiO₂ NPs will not bring in reliability problems. The packaging structure is as tight as commercial products.