Improvement of LED extraction efficiency with antireflection coating

It is very important to increase light extraction efficiency in LED structure design. The antireflection film technology is a simple and cost-cutting method. In this paper, we proposed a SiON layer as an antireflection coating deposited on the surface of the conventional AlGaInP LED which can be used to improve the performance of the chip. In the conventional AlGaInP LED, ITO thin film was deposited as current spreading layer. The propagation of lights through these layers was analyzed by transfer matrix method. The thicknesses of ITO and SiON layers have been optimized. SiON film was deposited by PECVD. The results of the experiments showed that optical power increased by 11.38% after LED packaged. The difference of peak wavelength between the two samples was less than 1nm.