Full InGaN red micro light emitting diodes: How to enhance the InN mole fraction

Micro-displays with pixel pitch smaller than 10 µm are required for augmented reality. The three primary colors can then be achieved with the same material: the InxGa1-xN alloy. However, when strained on GaN, its InN mole fraction x is limited to 25%. By using a full InGaN structure grown on a relaxed InGaN pseudo-substrate, such as the InGaNOS substrate from Soitec, the In incorporation rate is enhanced. An internal quantum efficiency higher than 10% at 640 nm an In content higher than 25% in InxGa1-xN/InyGa1-yN quantum wells will be shown. 10x10 µm² red micro-light emitting diodes will be also presented.