Nitride-based LEDs with ITO on nanostructured silicon contact layers

Nitride-based light-emitting diodes (LEDs) with indium-tin-oxide (ITO) on p-GaN, ITO on n+-short-period superlattice (SPS) and ITO on nanostructured silicon contact layers were fabricated. It was found that surface of the nanostructured silicon layer was very rough. It was also found that the 20 mA forward voltages measured from the LEDs with ITO on p-GaN, ITO on n+-SPS and ITO on nanostructured silicon contact layers were 6.01, 3.25 and 3.26 V, respectively. The small operation voltage observed from the LEDs with nanostructured silicon contact layer is probably due to the formation of a highly doped thin n+-GaN layer.