Aluminum nitride (AlN) is a key material for deep-ultraviolet (deep-UV) light-emitting diodes (LEDs). In AlN-based materials, the light emission intensity varies largely depending on the crystal plane because of its strong light polarization property as well as the quantum-confined Stark effect (QCSE). In this article, we introduce nonpolar plane AlN-based heterostructures working toward high-efficiency deep-UV LEDs.
