Fabrication and Optical Properties of White LED Based on Laminated Remote Phosphor Film

Based on laminated and remote phosphor packaging technology, double layer phosphor film were prepared by hot pressing method, the films then were packaged into white LED. Fluorescence spectrophotometer and the visible spectrum analysis system were used to study the influence of the layer order of green and red phosphor films and emission wavelength on the optical properties of white LED. Results show that the luminescent efficiency of radiation of blue-green-red type was improved by 31.69% compared to the blue-red-green type, the color fidelity and color gamut index increased with the increasing of wavelength of red phosphor film, the color fidelity and color gamut index reached the highest value 91 and 104 at 660nm respectively, in contrast, luminescent efficiency of radiation was inversely proportional to the wavelength; color fidelity decreased with the increasing of wavelength of green phosphor film, and color gamut index raised first, then decreased, the luminescent efficiency of radiation reach the highest value 300.7lm/W when emission wavelength of green phosphor film was 530nm.