Lumileds announces advances in red InGaN LEDs
Lumileds believes it is the first company to demonstrate that rich deep red light (615nm dominant wavelength corresponding with 635nm peak) can be produced with InGaN LEDs, with a Wall plug Efficiency of 7.5 percent at a current density of 10A/cm².
Lumileds says its breakthrough addresses the challenges associated with high indium concentrations including spectral peak shifts and broadening with current density.
InGaN is an attractive alternative to AlInGaP for creating red light sources because it harmonises manufacturing with Green and Blue LEDs, which are also based on InGaN. The large industrial capacity of InGaN gives economies of scale and is preferred for integration with silicon semiconductor manufacturing. InGaN Red is especially promising for microLED applications because of its characteristic to maintain efficiency at micron-scale sizes and low current density.
However, the current efficiency for sub-10-micron red microLEDs is an impediment to cost-effective and efficient microLED displays, according to Rob Armitage, Lumileds' director of Nitride Epitaxy Development. “Our work on Red InGaN validates our roadmap to meeting cost and efficiency thresholds for adoption,” he says.
In addition to demonstrating high-efficiency Red InGaN, Lumileds successfully established Red, Green, and Blue light emission from a single InGaN epitaxial stack. Subsequently, Lumileds translated this into microLEDs with excellent colour quality and electrical characteristics.
The integration of the three primary colours into single microLEDs has a tremendous impact on achieving low-cost high-yield microLED display assembly and will ultimately enable compact full-colour displays for Augmented Reality applications.
Note: Rob Armitage, is an invited speaker at the upcoming IWN 2024 conference where he will discuss the Development of InGaN LEDs for colour display applications.
