Micro light-emitting diode device

A micro light-emitting diode device, comprising:

• a substrate;
• a micro light-emitting diode having a lateral width smaller than 100 μm, disposed on the substrate, and comprising:
• a p-type GaN layer;
• an n-type Ill-nitride layer above the p-type GaN layer, wherein III refers to at least one of aluminum, gallium, and indium;
• an n-doped AlN layer above and in contact with the n-type Ill-nitride layer, wherein a thickness of the n-doped AlN layer is greater than 10 nm;
• and
• an active layer which emits light and is between the p-type GaN layer and the n-type III-nitride layer;
• and
• a transparent top electrode at least partially covering and in contact with the n-doped AlN layer,
• wherein a refractive index of the n-doped AlN layer is smaller than a refractive index of the n-type III-nitride layer,
• wherein a sum of thicknesses of the p-type GaN layer, the active layer, the n-type III-nitride layer, and the n-doped AlN layer is greater than 400 nm,
• wherein a sum of the thicknesses of the n-type III-nitride layer and the n-doped AlN layer is greater than a sum of the thicknesses of the active layer and the p-type GaN layer.