Advances in InGaN-based RGB micro-light-emitting diodes for AR applications: Status and perspective

Micro-light-emitting diodes (mu LEDs) are gathering significant interest as a technology for emerging micro-displays. However, mu LEDs encounter numerous obstacles, including size-dependent efficiency loss, poor efficiency of red mu LEDs, and challenges associated with the mass transfer and integration of full-color mu LEDs. These issues become more acute in ultra-small mu LEDs (<5 <mu>m), which were required by the augmented reality (AR) displays. Here, we discuss the principal challenges faced by mu LEDs and explore the possible solutions. We highlight recent advances in InGaN-based RGB mu LEDs tailored for AR displays. In particular, we discuss the advancements in ultra-small InGaN mu LEDs scaled down to 1 mu m, the developments in InGaN red mu LEDs, and the implementation of tunnel junction-based cascaded InGaN mu LEDs for monolithic integration.