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Effect of Dielectric Distributed Bragg Reflector on Electrical and Optical Properties of GaN-Based Flip-Chip Light-Emitting Diodes

Authors :
Shengjun Zhou
Haohao Xu
Mengling Liu
Xingtong Liu
Jie Zhao
Ning Li
Sheng Liu
Source :
Micromachines, Vol 9, Iss 12, p 650 (2018)
Publication Year :
2018
Publisher :
MDPI AG, 2018.

Abstract

We demonstrated two types of GaN-based flip-chip light-emitting diodes (FCLEDs) with distributed Bragg reflector (DBR) and without DBR to investigate the effect of dielectric TiO2/SiO2 DBR on optical and electrical characteristics of FCLEDs. The reflector consisting of two single TiO2/SiO2 DBR stacks optimized for different central wavelengths demonstrates a broader reflectance bandwidth and a less dependence of reflectance on the incident angle of light. As a result, the light output power (LOP) of FCLED with DBR shows 25.3% higher than that of FCLED without DBR at 150 mA. However, due to the better heat dissipation of FCLED without DBR, it was found that the light output saturation current shifted from 268 A/cm2 for FCLED with DBR to 296 A/cm2 for FCLED without DBR. We found that the use of via-hole-based n-type contacts can spread injection current uniformly over the entire active emitting region. Our study paves the way for application of DBR and via-hole-based n-type contact in high-efficiency FCLEDs.

Details

Language :
English
ISSN :
2072666X
Volume :
9
Issue :
12
Database :
Directory of Open Access Journals
Journal :
Micromachines
Publication Type :
Academic Journal
Accession number :
edsdoj.39dac91252b24036b2e050118b6056b1
Document Type :
article
Full Text :
https://doi.org/10.3390/mi9120650