A Power-Type Single GaN-Based Blue LED With Improved Linearity for 3 Gb/s Free-Space VLC Without Pre-equalization

A new GaN light-emitting diode (LED) structure, which has a 300-nm aluminum-doped zinc oxide transparent current spreading layer epitaxial layer grown on a standard GaN LED epistack used in commercial GaN LED products, shows improved power vs. voltage (P-V) linearity and is suitable for high-data rate visible light communication. Experimentally, a single GaN-based blue LED with a mesa diameter of 150 μm and a maximum optical power of 42 mW demonstrates a 3-Gb/s free-space data transmission speed. The modulation bandwidth reaches 600 MHz under the present experimental setup. The present work proves the practicability of enhancing the LED's free-space data transmission ability through a P-V linearity improvement at the chip level.