A crystal substrate is composed of a crystal of a nitride of a group 13 element and has a first main face and a second main face. The crystal substrate includes a low carrier concentration region and a high carrier concentration region both extending between the first main face and second main face. The low carrier concentration region has a carrier concentration of 10.sup.18/cm.sup.3 or lower and a defect density of 10.sup.7/cm.sup.2 or lower. The high carrier concentration region has a carrier concentration of 10.sup.19/cm.sup.3 or higher and a defect density of 10.sup.8/cm.sup.2 or higher.

An LED fabrication method includes forming impurity release holes by focusing a laser at the substrate back surface, and forming invisible explosion points by focusing a laser inside the substrate on positions corresponding to the impurity release holes; communicating the impurity release holes with the invisible explosion points to release impurities generated during forming of the invisible explosion points from the substrate through the impurity release holes, thereby avoiding low external quantum efficiency resulting from adherence of impurities to the side wall of the invisible explosion points. By focusing on a position with 10 μm˜40 ˜m inward from the substrate back side, adjusting laser energy and frequency to burn holes inside the substrate to penetrate and expose the substrate back surface, thereby effectively removing by-products, and reducing light absorption by such by-products, light extraction from a side wall of the LED can also be improved and light extraction efficiency is enhanced.

Epitaxial formation support structures and associated methods of manufacturing epitaxial formation support structures and solid state lighting devices are disclosed herein. In several embodiments, a method of manufacturing an epitaxial formation support substrate can include forming an uncured support substrate that has a first side, a second side opposite the first side, and coefficient of thermal expansion substantially similar to N-type gallium nitride. The method can further include positioning the first side of the uncured support substrate on a first surface of a first reference plate and positioning a second surface of a second reference plate on the second side to form a stack. The first and second surfaces can include uniformly flat portions. The method can also include firing the stack to sinter the uncured support substrate. At least side of the support substrate can form a planar surface that is substantially uniformly flat.

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

The disclosed technology relates generally to a method and system for micro assembling GaN materials and devices to form displays and lighting components that use arrays of small LEDs and high-power, high-voltage, and or high frequency transistors and diodes. GaN materials and devices can be formed from epitaxy on sapphire, silicon carbide, gallium nitride, aluminum nitride, or silicon substrates. The disclosed technology provides systems and methods for preparing GaN materials and devices at least partially formed on several of those native substrates for micro assembly.

The group III nitride semiconductor light emitting element according to this disclosure has, on a substrate, an n-type semiconductor layer, a light emitting layer, a p-type AlGaN electron blocking layer, a p-type contact layer and a p-side reflection electrode, in this order, wherein, a center emission wavelength of light emitted from the light emitting layer is 250 nm or greater and 330 nm or smaller, the Al composition ratio of the p-type AlGaN electron blocking layer is 0.40 or greater and 0.80 or smaller, the film thickness of the p-type contact layer is 10 nm or greater and 50 nm or smaller, and the p-type contact layer has a p-type AlGaN contact layer having Al composition ratio of 0.03 or greater and 0.25 or smaller.

There is provided a method for manufacturing a nitride semiconductor template, including the steps of: growing and forming a buffer layer to be thicker than a peak width of a projection and in a thickness of not less than 11 nm and not more than 400 nm on a sapphire substrate formed by arranging conical or pyramidal projections on its surface in a lattice pattern; and growing and forming a nitride semiconductor layer on the buffer layer.

A method of manufacturing an optoelectronic device including light-emitting diodes comprising forming three-dimensional semiconductor elements, extending along parallel axes, made of a III-V compound, with a polarity of the group-III element, the method further including, for each semiconductor element, forming an active area covering the semiconductor element and a stack of semiconductor layers covering the active area, the active area being formed by vapor deposition at low pressure and comprising quantum wells separated by barrier layers, each quantum well including a ternary alloy having at least one first group-III element, the group-V element, and a second group-III element, the ratio of the atomic flux of the group-III elements to the atomic flux of the group-V element is in the range from 1 to 1.8.

A dislocation-free GaN/InGaN-based nanowires-LED epitaxially grown on a transparent, electrically conductive template substrate. The simultaneous transparency and conductivity are provided by a thin, translucent metal contact integrated with a quartz substrate. The light transmission properties of the translucent metal contact are tunable during epitaxial growth of the nanowires LED. Transparent light emitting diodes (LED) devices, optical circuits, solar cells, touch screen displays, and integrated photonic circuits can be implemented using the current platform.

A light-emitting device, includes a substrate structure, including a base portion having a surface and a plurality of protrusions regularly formed on the base portion; a buffer layer covering the plurality of protrusions and the surface; and III-V compound semiconductor layers formed on the buffer layer; wherein one of the plurality of protrusions includes a first portion and a second portion formed on the first portion and the first portion is integrated with the base portion; and wherein the base portion includes a first material and the first portion includes the first material.