Mechanisms of enhanced light emission in GaN-based light-emitting diodes by V-shaped micropits

Hyun Jeong (1, 2) , Ji-Hee Kim (2) , Chang-Hee Hong (3) , Eun-Kyung Suh (3) , Mun Seok Jeong (2)

1 LNIO - Laboratoire de Nanotechnologie et d'Instrumentation Optique
2 SKKU - Sungkyunkwan University [Suwon]
3 Chonbuk National University

We have investigated the light emission mechanisms of V-shaped, hexagonal-micropit-arranged, InGaN/GaN light-emitting diodes (HMA-LEDs). By near-field scanning optical microscopy and the confocal scanning electroluminescence microscopy, we found that enhanced light output of HMA-LED was significantly contributed by not only improved light-extraction efficiency but also locally improved crystalline quality near the micropit. Etch pit density and cross-sectional transmission electron microscope image indicate that threading dislocation (TD) bending lead to decrease the TD density near the micropit. Furthermore, partially linearly polarized light from the inclined facets of the HMA-LEDs was observed.

Keywords: Chemical vapor deposition; Gallium nitride light emitting diodes; High numerical aperture optics; Near field microscopy; Scanning electron microscopy; Total internal reflection

Domains: Engineering Sciences [physics]; Optics / Photonic

Hyun Jeong, Ji-Hee Kim, Chang-Hee Hong, Eun-Kyung Suh, Mun Seok Jeong. Mechanisms of enhanced light emission in GaN-based light-emitting diodes by V-shaped micropits. Optical Materials Express, 2015, 5 (6), pp.1306. ⟨10.1364/OME.5.001306⟩. ⟨hal-02382637⟩