White Light Emission Characteristics of Polymer-Encapsulated CdSe Nanocrystal Films

A white, cadmium selenide (CdSe) nanocrystal-based phosphor light-emitting diode (LED) was fabricated in this work using a commercial ultraviolet (UV) LED topped with a thin film of nanocrystals encapsulated in a polymer. A range of film thicknesses were fabricated and different wavelength LEDs were employed to analyze their influences on the emission properties of the phosphor LEDs. The absorbance and emission intensity of light passing through the films were optimized without compromising the excellent inherent color quality of the white-light nanocrystals. These results indicate a potential to improve the color quality and lower the scattering losses found in current white LEDs based on much larger, micron-sized phosphors.