Beamed enhanced emission from nanoantennas for solid state lighting

摘要

The introduction of white LEDs is leading to the solid state lighting revolution with the fast replacement of incandescent lamps by much more efficient light sources. In white LEDs, high efficiency UV or blue LEDs are used to excite the luminescence of a high quantum efficiency (QE) material called phosphor. Much effort is dedicated to the development of stable phosphors with the highest possible QE and with designed absorption and emission spectra. These efforts are also on the design of optical elements to couple light out of the devices and to beam this light in certain directions. Large improvements and control of the emission can be achieved with resonant nanostructures. By coupling the phosphor to arrays of nanoparticles, which work as tiny antennas for light, we have demonstrated an up to 70-fold enhancement of a defined emission wavelength in certain directions. This extraordinary enhancement can lead to the replacement of bulky optical components in LEDs by nanostructures.