Highly Efficient GaN-Based LEDs with Photonic Crystals Replicated from Patterned Si Substrates

We report on highly efficient GaN-based light emitting diodes (LEDs) with the photonic crystals (PhC) which are initially patterned on Si substrates. The PhC structures are replicated at the LED bottom by hetero-epitaxial growth and a subsequent wafer-transfer technique. Owing to the synergetic effects of the higher crystal quality obtained by lateral growth on the patterned Si substrate and the increased optical emission by PhC, resultant LEDs with the PhC achieved enhanced output power by 70% compared with that without patterned Si substrate. The present technology will open a new era of low-cost and bright blue LEDs