Native Defect Luminescence of Zinc Oxide Films and Its Potential Application as White Light Sources

ZnO light-emitting diodes (LEDs) have an enormous potential in lighting applications. The major issue to be resolved is the generating and control of light emissions. This issue arises from the variation and combination in LED wavelength. We found that defect luminescence of ZnO has a varied wide range of wavelength, which suits to an application of LED for white-light generation. We have shown both experimentally and theoretically that defect emission can be used in ZnO systems. This type of defect has the advantage of not requiring extensive and costly factory systems comparing with traditional doped materials and others. We not only propose potential application of native defect luminescence of Zinc Oxide film for white LEDs-flat light sources, but also have some methods to control defect origins, a certain center position and broad range of the emission band of ZnO film in the initial stage. According to different preparing method and certain experiment conditions, variant white such as whitish and bluish-white etc., primary and important colors- blue bands (455, 458 nm), green bands (517, 548 nm), red bands (613, 569 nm) are obtained respectively. This proved that it is a better road to one white light LED with one kind of material -ZnO.