Multifunctional Ultraviolet-C Micro-LED With Monolithically Integrated Photodetector for Optical Wireless Communication

In this paper, a multifunctional ultraviolet-C (UVC) micro-LED with monolithically integrated photodetector (PD) based on AlGaN multiple quantum wells (MQWs) was fabricated. We designed and integrated UVC LED with sizes of 40 and 300 
$\mu$
m emitted at 277 nm on a single chip which also serve functions as PDs and further studied the performance of on-chip real-time photodetection. The photocurrent generated from one LED can well reflect the light output power of the adjacent LED. Furthermore, both 40 
$\mu$
m UVC micro-LED and 300 
$\mu$
m UVC LED play important roles in high speed UVC communication with record bandwidths of 497.58 MHz for 40 
$\mu$
m micro-LED and 467.38 MHz for 300 
$\mu$
m LED, offering each other as backup light source in high speed UVC communication. And the data transmission rates of 1.6 Gbps for 40 
$\mu$
m micro-LED and 1.21 Gbps for 300 
$\mu$
m LED over 1 m link based on the 16-ary quadrature amplitude modulation orthogonal frequency division multiplexing (16-QAM-OFDM) with pre-equalization were achieved. The multifunctional UVC micro-LED monolithically integrated PD, without the need for an external PD to monitor the fluctuations in the luminescence, providing high stability for diverse applications, such as spatial wireless communication for 6 G communication.