US Patent 11688829 Engineered substrate architecture for InGaN red micro-LEDs

A light emitting diode (LED) device includes a substrate and a plurality of mesa structures. Each mesa structure includes a layer of a first semiconductor material, a porous layer of the first semiconductor material on the layer of the first semiconductor material, and a layer of a second semiconductor material on the porous layer. The porous layer is characterized by an areal porosity ≥15%. The second semiconductor material is characterized by a lattice constant greater than a lattice constant of the first semiconductor material. Each mesa structure also includes an active region on the layer of the second semiconductor material and configured to emit red light, a p-contact layer on the active region, a dielectric layer on sidewalls of the p-contact layer and the active region, and an n-contact layer in physical contact with at least a portion of sidewalls of the layer of the second semiconductor material.