Performance Improvement of VLC System Using GaN-Based LEDs With Strain Relief Layers

The GaN-based blue light-emitting diodes (LEDs) with superlatticelike strain relief layer (SRL) and without SRL were fabricated by metal organic vapor phase epitaxy (MOVPE). The luminescence characteristics of the different LEDs were measured experimentally and calculated theoretically. It is demonstrated that the efficiency droop of GaN-based LEDs is suppressed using the SRL due to the reduction of polarization electric field in quantum wells. This is beneficial to the mitigation of LED light output power-injection current (L-I) nonlinearity. Furthermore, using the different LEDs as light source, the performance of visible-light communication (VLC) system was also investigated. The results reveal that the VLC system performance is improved when the LEDs with SRL are applied. The reason is that the transmitted signal error decreases as the LED L-I nonlinearity mitigates. As a result, the GaN-based LEDs with SRL can be applied in the VLC to improve the system performance.