Recent Progress in III‐Nitride Tunnel Junction Light‐Emitting Diodes

Abstract

The emergence of III‐nitride semiconductors has established a solid foundation for the development of high‐efficiency optoelectronic devices, particularly for light‐emitting diodes (LEDs). However, the efficiency improvement for LEDs is typically restricted by hole injection and optical loss. The incorporation of tunnel junction (TJ) into structure of LEDs has arisen as a promising solution to overcome these challenges while providing additional features, such as electrical contacts, current confinement, and novel controllability in band engineering. Herein, recent progress in the development of III‐nitride TJ LEDs is reviewed. It is started with an explanation of the working principles of TJ and several approaches for enhancing the tunneling probability of TJ are discussed. Subsequently, the most popular techniques for TJ fabrication are summarized and critical issues involved in these processes are discussed. Moreover, applications of TJ in UV LEDs, cascaded LEDs, and micro‐LEDs are highlighted. Finally, an outlook on potential prospects of TJ for the development of high‐performance LEDs is presented.