Performance improvement of ultraviolet-A multiple quantum wells using a vertical oriented nanoporous GaN underlayer

Abstract

Well-aligned, lateral and vertical oriented nanoporous GaN was fabricated using the electrochemical etching procedure and its influence on the optical characteristics of ultraviolet-A multiple quantum well (MQW) structure was investigated. We used a MQW structure with a V-defect and n-Al0.1Ga0.9 N layer, which greatly improved the uniformity of vertical electrochemical etching. Compared to the as-grown MQW structure, the lateral and vertical oriented nanoporous MQW structures have 3.8-fold and 8.1-fold photoluminescence intensity enhancement and the full width at half maximum has been narrowed from 18.4 nm to 7.9 nm and 2.8 nm, respectively. The vertical oriented nanoporous MQW structure has a rectangular far-field emission pattern with uniform forward light distribution and the view angle of 85% intensity is 50°. This study provides an effective method for improving the light output and controlling the emission angle of GaN based light emitting devices, as well as a method for preparing well-aligned nanopores in semiconductors.

Effect of distributed Bragg reflectors on photoluminescence properties of CH3NH3PbI3 film

“…1 b). The PL enhancement of the perovskite film grown the etched single-layer GaN can be contributable to scattering and reflection of nanopores, leading to amplify spontaneous emission (ASE) by resonant cavity 24 . The ASE occurs before the light output.…”

Defect-selective-etched porous GaN as a buffer layer for high efficiency InGaN/GaN light-emitting diodes

“…demonstrated well-controlled ECE of p-type GaN under a constant bias using a tunnel junction between the p- and n-GaN layers to inject the hole carriers for etching to occur at the p-GaN/solution interface [ 31 ]. The ECE is not only simple, but also a very efficient and precise fabrication approach for generating porous GaN layer [ 25 , 32 , 33 ]. In this study, we employed an ECE approach standardized by our group [ 34 ], in order to maintain the etch pattern size in the nanoscale regime.…”