Rational Distributed Bragg Reflector Design for Improving Performance of Flip-Chip Micro-LEDs

The distributed Bragg reflector (DBR) has been widely used in flip-chip micro light-emitting diodes (micro-LEDs) because of its high reflectivity. However, the conventional double-stack DBR a strong angular dependence and narrow reflective bandwidth. Here, we propose wide reflected angle Ti3O5/SiO2 (WRA-DBR) for AlGaInP-based red GaN-based green/blue micro-LEDs (RGB micro-LEDs) to overcome drawbacks DBR. WRA-DBR consisting six sub-DBRs reflectivity within visible light wavelength region at an incident ranging from 0° 60°. Furthermore, influence on performances RGB is numerically investigated based finite-difference time-domain method. Owing higher less WRA-DBR, with have stronger electric field intensity top side comparison DBR, which indicates that more photons can be extracted WRA-DBR.