Tsinghua University and Beijing National Laboratory for Condensed Matter Physics in China have reported on the use of freestanding gallium nitride substrates (FGS) for red indium gallium nitride (InGaN) micro-light-emitting diodes (LEDs) in terms of efficiency and uniformity across arrays of devices [Luming Yu et al, Appl. Phys. Lett., v123, p232106, 2023]. The researchers claim that InGaN red micro-LEDs with etching-defined mesa size <5μm have not previously been reported. Although it is difficult to achieve high efficiency using indium gallium nitrid...