A method for fabricating an (Al,Ga,In,B)N or III-nitride semiconductor device, including performing a growth of III-nitride or (Al,Ga,In,B)N material including a p-n junction with an active region and using metal-organic chemical vapor deposition (MOCVD) or chemical vapor deposition; and performing a subsequent regrowth of n-type (Al,Ga,In,B)N or III-nitride material using MOCVD or chemical vapor deposition while utilizing a pulsed delta n-type doping scheme to realize an abrupt, smoother surface of the n-type material and a higher carrier concentration in the n-type material. In another example, the method comprises forming a mesa having a top surface; and activating magnesium in the p-type GaN of the (Al,Ga,In,B)N material through openings in the top surface that expose the p-type GaN's surface. The openings are formed before or after the subsequent regrowth of the tunnel junction.

An optoelectronic device including a matrix of axial light-emitting diodes (LEDs). Each LED includes an active layer emitting electromagnetic radiation. The matrix forms a photonic crystal having at least first and second resonant peaks in a plane containing the active layers, each first and second peak amplifying the radiation intensity at a first and second wavelength respectively. Each light emitting diode includes an elongated semiconductor element, having a first portion of a first average diameter, a second portion extending the first portion and having a cross-sectional area decreasing away from the first portion, and the active layer extending the second portion and having a second average diameter strictly less than the first average diameter, the active layers being located at the first peak locations and absent at the secondary peak locations.

Disclosed are an LED structure, an LED device and a manufacturing method for the LED structure. The LED structure includes a substrate structure including a substrate and a plurality of first stress modulation layers located on the substrate periodically and separately; and a light-emitting unit located on the substrate structure; wherein the substrate structure includes a first region of which upper surface is the first stress modulation layer and a second region of which upper surface is the substrate, and a light-emitting unit located on the first region and a light-emitting unit located on the second region have different light-emitting wavelengths, which realizes a light-emitting unit with two kinds of main light-emitting wavelengths on the same substrate.