# Enhanced Emission and Polarization Control of Green GaN-Based Resonant Cavity LEDs with Porous Distributed Bragg Reflectors

## TL;DR

Researchers improved green LEDs by using porous structures and mirrors to control light emission and polarization for better performance in displays and fiber optics.

## Contribution

The integration of porous GaN and dielectric DBRs in green RC-LEDs enables enhanced emission control and polarization.

## Key findings

- Porous-GaN DBRs achieved 98% reflectivity with a stopband at 566 nm.
- RC-LEDs showed a narrower EL spectrum fwhm of 12.8 nm compared to 41 nm in nontreated LEDs.
- Polarization analysis revealed two spectral peaks with directional fwhm variation (5.2 nm at 0°, 6.4 nm at 90°).

## Abstract

Green InGaN-based resonant-cavity light-emitting diodes
(RC-LEDs)
with integrated nanoporous (NP) GaN distributed Bragg reflectors (DBRs)
were fabricated by using a selective electrochemical (EC) etching
technique. The epitaxial structure comprised 25 alternating Si-doped
GaN layers, forming a periodic high- and low-refractive-index stack
after the EC etching process. The resulting porous-GaN DBR exhibited
an effective refractive index of 2.02 and a stopband centered at 566
nm, achieving 98% reflectivity. By integrating a top-3-pairs dielectric
mirror, the electroluminescence (EL) spectra showed a narrower full
width at half-maximum (fwhm) from 41 nm (nontreated LED) to 12.8 nm
(RC-LED). Polarization analysis revealed two spectral peaks at 536.7
and 544.7 nm, with one suppressed by a polarizer. The fwhm varied
with the polarization direction, being 5.2 nm at 0° and 6.4 nm
at 90°. These results demonstrate that integrating bottom porous
GaN and top dielectric DBRs yields a high-reflectivity, low-loss RC
structure suitable for high light coupling in fiber interconnection
and high-color-purity micro-LED display applications.