High-Efficiency Nitride-Based Light-Emitting Diodes with Moth-Eye Structure

Nitride-based blue light-emitting diodes (LEDs) with a moth-eye structure on the back of a 6H–SiC substrate have been developed. The moth-eye LED has a roughness less than the optical wavelength at the back surface of the SiC substrate fabricated by reactive ion etching (RIE) with CF4 gas. The light extraction efficiency and corresponding output power have been increased to 3.8 times those of a LED with a conventional structure. The experimental findings agree with the results of a theoretical analysis of the effect of the moth-eye structure.