Enhanced light output in double roughened GaN light-emitting diodes via various texturing treatments of undoped-GaN layer

An InGaN-GaN light-emitting diodes (LEDs) with double roughened (p-GaN and undoped-GaN) surfaces were successfully fabricated by surface-roughening, wafer-bonding and laser lift-off technologies. The effect of the roughness of the undoped-GaN layer on the performance of double roughened LEDs was investigated. It was found that the rms roughness of the undoped-GaN layer increased from 18.6 to 146.7 nm, the output power increased from 7.2 to 10.2 mW, and view angle decreased from 133.6 to 116°.