Improved light extraction from large-area vertical light-emitting diodes with deep hole-patterns using nanosphere lithography.

The authors report on an improved light extraction method from large-area vertical light emitting diodes (VLEDs) with deep hole-patterns fabricated using nanosphere lithography. In order to produce the ordered deep-hole patterns on the n-type GaN surface, a 150 nm thick Ni dot mask formed via a lift-off process of the Ni coated onto a 500 nm diameter polystylene bead array was employed to enable deep etching. Three VLEDs-one as a reference with no patterns, and two with periodic 360 nm diameter hole patterns, one with 1.