Paper accepted in Japanese Journal of Applied Physics (Invited review)!

[Abstract] InGaN-based light-emitting diodes (LEDs) are efficient light sources in the blue-green light range and have been successfully commercialized in the last decades. Extending their spectral range to the red region causes a significant reduction in LED efficiency. This challenge hinders the integration of red, green, and blue LEDs based on III-nitride materials, especially for full-color micro-LED displays. We review our recent progress on InGaN-based red LEDs, including the epitaxial structures and device fabrication. We also present the optical performance of InGaN red LEDs with different chip sizes from hundreds to tens of micrometers.