Nonpolar GaN-based nanopillar green light-emitting diode (LED) fabricated by using self-aligned In_3Sn nanodots

摘要

We fabricate nonpolar InGaN/GaN single quantum-well based a-plane nanopillar green light-emitting diode (LED). The top-down fabrication method was used for fabricating nanopillar LED from the planar LED, where self-aligned In3Sn nanodots were used as an etching mask. Fabricated nanopillars have high yield with large height-to-diameter aspect ratio found by scanning-electron-microscopy characteristics. The size of nanopillars depends on the size of In3Sn nanodots which are fabricated from the ITO (indium tin oxide) thin film by 3% HCl solution. It is systematically investigated that the size of nanodots depends on the ITO thickness rather than the etching time. In order to achieve uniform current injection into nanopillars, a p-type transparent ITO contact is selectively deposited on the top of each nanopillar. The ITO contact layer consists of a slanted oblique-angle (85 degrees/-85 degrees) layer followed by a thick blanket layer for uniform current distribution. The macroscopic optoelectronic characteristics show the uniform current distribution over the chip area, which is also interactively explained.