Effect of periodic deflector embedded in InGaN∕GaN light emitting diode

This letter proposes a concept of $\mathrm{In}\mathrm{Ga}\mathrm{N}∕\mathrm{Ga}\mathrm{N}$ light emitting diodes with periodic deflector embedded structure (PDE-LED). The PDE-LED was grown on a sapphire substrate with $\mathrm{Si}{\mathrm{O}}_2$ hexagonal patterned mask using selective metal-organic chemical deposition. More than 200 artificial inverted polygonal pyramids (AIPPs), which included six $R$ planes and six $N$ planes deflectors with inclined angles of 57° and 61°, respectively, were formed and periodically distributed on masked area. These AIPP deflectors revealed a superior capability of enhancing light extraction efficiency mainly because the AIPP deflector structure could provide multiple chances for photons to escape from the LED sidewall as opposed to a rectangular conventional LED. Thus, the light output power of the PDE-LED was 1.51 times higher than that of a conventional LED at an injection current of $20\mathrm{mA}$ , while forward bias voltage and leakage current were compatible to those of conventional LEDs.