Unidirectional luminescence from InGaN/GaN quantum-well metasurfaces

• Published in: Nature photonics Vol. 14; no. 9; pp. 543 - 548
• Main Authors: Iyer, Prasad P., DeCrescent, Ryan A., Mohtashami, Yahya, Lheureux, Guillaume, Butakov, Nikita A., Alhassan, Abdullah, Weisbuch, Claude, Nakamura, Shuji, DenBaars, Steven P., Schuller, Jon. A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2020; Nature Publishing Group
• Subjects: 142/126; 639/624/1020/1089; 639/624/399/1015; 639/624/400/1021; 639/925/357/1015; Applied and Technical Physics; Frequency dependence; Gallium nitrides; Incident waves; Indium gallium nitrides; Letter; Light emission; Light emitting diodes; Locking; Metamaterials; Metasurfaces; Optical components; Optics; Physics; Physics and Astronomy; Quantum efficiency; Quantum Physics; Quantum wells; Waveforms
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/s41566-020-0641-x

III–nitride light-emitting diodes (LEDs) are the backbone of ubiquitous lighting and display applications. Imparting directional emission is an essential requirement for many LED implementations. Although optical packaging 1 , nanopatterning 2 , 3 and surface roughening 4 techniques can enhance LED extraction, directing the emitted light requires bulky optical components. Optical metasurfaces provide precise control over transmitted and reflected waveforms, suggesting a new route for directing light emission. However, it is difficult to adapt metasurface concepts for incoherent light emission, due to the lack of a phase-locking incident wave. Here, we demonstrate a metasurface-based design of InGaN/GaN quantum-well structures that generate narrow, unidirectional transmission and emission lobes at arbitrary engineered angles. We further demonstrate 7-fold and 100-fold enhancements of total and air-coupled external quantum efficiencies, respectively. The results present a new strategy for exploiting metasurface functionality in light-emitting devices. Exploiting two-dimensional metamaterials, the direction of emission from InGaN/GaN quantum wells is engineered while simultaneously improving quantum efficiency.