Enhanced Optical Power of GaN-Based Light-Emitting Diode with Nanopatterned p-GaN by Simple Light Coupling Mask Lithography

Abstract

We report the enhancement of the optical output power of GaN-based blue light-emitting diode (LED) with two-dimensionally nanopatterned p-GaN fabricated using a novel light coupling mask with soft-lithographically defined light aperture arrays. This light coupling mask provided a simple and reproducible process to generate patterns with a regular hole size of 550 nm on p-GaN. The LED with nanopatterned p-GaN showed light output power improved by 11.2% at an input current of 20 mA compared with the LED with flat p-GaN, even with slightly degraded electrical properties owing to the formation of etching-induced defects in the p-GaN.

Performance of GaN-Based LEDs with Nanopatterned Indium Tin Oxide Electrode

“…To increase the LEE of LEDs, several approaches had focused on fabricating micro-/nanostructures either inside or outside the LEDs [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. For example, roughed GaN surface [3][4][5][6][7], roughed sapphire substrate [8,9], roughed indium tin oxide (ITO) surface [10][11][12], and grown ZnO micro-/nanostructures [13][14][15] have been implemented in LEDs. The common nanoscale patterning techniques, such as electron-beam lithography [16], nanoimprint lithography [17], holographic lithography [18], hydrothermally method [19], and nanosphere lithography (NSL) [20], are used to obtain nanoscale surface textures.…”

Enhancing light extraction of GaN-based blue light-emitting diodes by a tuned nanopillar array

“…[4] The majority of photons are reflected from the interface, become guided light in a waveguide formed by GaN and get reabsorbed. To increase the light extraction efficiency, various methods, such as roughed p-GaN surface, [5][6][7][8][9] roughed sapphire substrate, [10,11] photonic crystal [12][13][14][15][16] and patterned indium tin oxide (ITO) surface, [17][18][19] have been implemented in InGaN-based LEDs.…”