True‐Red InGaN Light‐Emitting Diodes for Display Applications

Red InGaN has attracted much attention recently for microLED display applications. However, the consequences of spectral broadening are often overlooked and many of the published spectra do not meet display gamut requirements. We focus on maximizing the red InGaN radiance with a spectrum capable of meeting the DCI‐P3 standard (dominant wavelength of ∽615 nm). The maximum radiance for LEDs meeting said requirement is obtained at 20 A/cm2 and corresponds to 4% WPE in large‐area encapsulated devices. The WPE can be increased to 12.5% using epitaxy of lower In concentration driven at 2 A/cm2. We also report data for microLEDs fabricated from similar red InGaN epitaxy. No size dependence of the IQE or spectra are observed down to the smallest sizes studied (∽2 microns). We have further leveraged our expertise with red InGaN and nitride tunnel junctions to demonstrate polychromatic microLEDs with independent control of red, green, and blue emission within single pixels of 9x12 micron dimensions. These devices are grown in a single growth run on the same sapphire substrate wafer using methods proven in high‐volume epitaxy manufacturing.This article is protected by copyright. All rights reserved.