基于蓝绿光Micro-LED的可见光通信芯片调制带宽研究

Study on Modulation Bandwidth of Blue-green Micro-LEDs for Visible Light Communication

基于氮化镓微米LED(Micro-LED)的可见光通信(Visible Light Communication,VLC)技术成为近年来的研究热点。通过深紫外光刻技术制备了小尺寸的氮化镓基蓝/绿光Micro-LED芯片,深入研究了40~10μm不同尺寸Micro-LED器件的性能,以及其作为VLC光源的调制带宽能力。研究发现,随着LED器件尺寸的缩小,其调制带宽显著增加。通过在电极间加入电磁屏障以及对LED器件侧壁进行钝化修复,直径为10μm的绿光Micro-LED亮度可达1×10^(8) cd/m^(2),直径为20μm的蓝光Micro-LED的调制带宽可达372.6MHz。研究结果表明,基于氮化镓的Micro-LED芯片在调制带宽上仍有较大的提升空间,经过进一步的研究,有望推动高速可见光通信的系统应用。

Using GaN-based micron-sized LEDs(Micro-LEDs)as the light source for visible light communication(VLC)systems has become a hot research topic in recent years.In this paper,Micro-LED devices with different sizes from 40~10μm have been designed and fabricated by deep UV lithography.The optoelectronic characteristics of GaN-based Micro-LEDs as well as modulation bandwidth performance were systematically investigated.It is found that the modulation bandwidth can be significantly increased by decreasing the device size.By optimizing sidewall passivation and electromagnetic shielding,high brightness as much as 1×10^(8) cd/m^(2) has been acquired by the green Micro-LED chip with 10μm in diameter.Furthermore,the modulation bandwidth of a single blue Micro-LED of 20μm can reach 372.6 MHz.The results show that higher modulation bandwidth can be expected for the GaN-based Micro-LED chip,and it is expected to promote the application of high-speed visible light communication system in the near future.