Micro-Light Emitting Diode: From Chips to Applications

Typical light-emitting diodes (LEDs) have a form factor >(300 x 300) mu m(2). Such LEDs are commercially mature in illumination and ultralarge displays. However, recent LED research includes shrinking individual LED sizes from side lengths >300 mu m to values <100 mu m, leading to devices called micro-LEDs. Their advent creates a number of exciting new application spaces. Here, a review of the principles and applications of micro-LED technology is presented. In particular, the implications of reduced LED size in necessitating mitigation strategies for nonradiative device edge damage as well as the potential for higher drive current densities are discussed. The opportunities to integrate micro-LEDs with electronics, and into large-scale arrays, allow pixel addressable scalable integrated displays, while the small micro-LED size is ideal for high-speed modulation for visible light communication, and for integration into biological systems as part of optogenetic therapies.