Large modulation bandwidth GaN-based micro-LED arrays on Si Substrates with graded In composition barriers

With the increasing wireless capacity demand for in sixth-generation (6G) networks exacerbating the issue of spectrum scarcity, high-speed visible light communication (VLC) based on GaN-based light-emitting diodes (LEDs) has emerged as a crucial supplementary solution. However, the lack of LED performance severely limits the development of VLC. Herein, the blue micro-LED array with the gradient of In component in the InxGa1-xN quantum barrier (QB) was demonstrated. Among them, the micro-LED array of two QBs with linearly increasing In component along [0001] direction serves to effectively suppress the polarization electric field, thereby increasing the radiative recombination efficiency and carrier concentration. At the current density of 2000 A/cm
²
, the light output power (LOP) is 28.9 mW, and the -3 dB bandwidth reaches 580 MHz, approximately 34% higher than that of the GaN barrier. This work presents a novel and simple strategy for realizing a high modulation bandwidth micro-LED array.