Transmission efficiency study of grating layer location of a GaN nano-grated structure

This is a study regarding nano-grating structure location of GaN LEDs. A 2D model of a nano-grating GaN LED is developed and used for simulations. The analyses focus on enhancement of light extraction efficiency (LEE) through the surface grating location optimization in relation to the Multi-quantum well (MQW) source region. By studying the effects of source location on the total light transmission across the GaN surface-air interface, we find that, as the location of the grating surface increases, or in other words the distance between the grating surface and the source increases, there is a general improvement in the enhancement of the transmission. However, compared to the non-grating case, some locations can improve the LEE by up to 133%, while the other locations may reduce LEE. We find that optimizing location increases invariance of transmission to the surface grating period.