Surface Plasmon Enhanced Light-Emitting Diode with Hybrid Microcavity Spacing

The light emission of LED structures can be enhanced by coupling to surface plasmons by using a periodic pattern formed on the top semitransparent metal layer resulting in microcavities. The improved light emission results from trapping of pump photons within the microcavity. The spacing between the microcavities has a strong impact on the light emission characteristics. In this paper, the LED structure with hybrid pattern of spacing interval is developed. The spacing between the silver stripes is same on both the ends in the top layer whereas the spacing between the middle two stripes are kept wider. The electromagnetic field distribution for TE and TM modes is investigated for this approach and compared with the structure of uniform spacing interval. Results show that there is an improvement in the field distribution in TE mode in the structure with hybrid spacing interval when compared with the structure with uniform interval.