The influences of pattern size and etching depth of patterned sapphire substrates (PSSs) on crystal quality and light output power of light-emitting diodes (LEDs) were investigated by contact-transferred and mask-embedded lithography. The present results indicate that a smaller pattern size facilitates superior light extraction efficiency. However, a suitable pattern size and etching depth should be chosen to obtain the highest quality of GaN film. In comparison with the conventional sapphire substrate, the largest light output enhancement (̃28:9%) was observed when the pattern diameter and the etching depth of PSS were 400 and 400 nm, respectively.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)