8 results about "Sapphire substrate" patented technology

The invention discloses an LED vertical chip structure and a manufacturing method. The LED vertical chip structure sequentially comprises a substrate, a graphene layer, a ZnO nanometer wall/ GaN, an n-GaN layer, an InGaN/ GaN multiple quantum well and a p-GaN from bottom to top. Compared with a traditional sapphire substrate LED chip, the LED vertical chip structure is large in lighting area and strong in heat dissipation capacity and has no current blocking effect. Meanwhile, due to the fact that the LED vertical chip directly extends outwards and grows, compared with a vertical structure LED prepared through a peeling-bonding technology, the LED vertical structure has the advantages that the processes of peeling and bonding are removed, the processes are simplified, and yield is high.

The invention relates to a large-power forward LED chip structure comprising a transparent passivating layer, a P pressure welding point, a transparent electrode layer, an N electrode, an LED epitaxial layer, a sapphire substrate and a reflection solder layer, wherein the surface of the reflection solder layer forms a DBR optical reflection layer in the mode of optical coating; and the bottom of the reflection solder layer is provided with a high heat conduction substrate layer. The large-power forward LED chip of the invention combines the heat conduction substrate with the DBR optical reflection film to solve the problem of heat dissipation and light emitting efficiency improvement for the large-power LED chip when high-current density is small.

The invention discloses a preparation method of a light emitting diode epitaxial wafer, and belongs to the technical field of a semiconductor. The preparation method comprises the steps of providing an AlN sapphire substrate; enabling a non-doped gallium nitride layer to be grown on the AlN sapphire substrate; enabling an N type gallium nitride layer to be grown on the non-doped gallium nitride layer; enabling a multi-quantum-well layer to be grown on the N type gallium nitride layer; enabling an electron barrier layer to be grown on the multi-quantum-well layer; and enabling a P type galliumnitride layer to be grown on the electron barrier layer, wherein the electron barrier layer is a P type doped aluminum gallium nitrogen layer; and the surface, for growing the P type gallium nitride layer, of the electron barrier layer is a nitrogen polarized surface. By setting the surface, with the P type gallium nitride layer, of the electron barrier layer into the nitrogen polarized surface, the contact between the electron barrier layer and the P type gallium nitride layer is closer due to the fact that the nitrogen polarized surface is more uneven in a concave and convex manner than themetal polarized surface, so that the ohmic contact resistance is low, the short channel effect is weak, hole injection can be promoted, the recombination efficiency of holes and electrons can be improved, and the luminous efficiency of the light emitting diode is improved.

The invention relates to a preparation method and application of a wafer-level absolute single-layer transition metal chalcogenide. The preparation method comprises the following steps that (1) first annealing treatment is carried out on a sapphire substrate to obtain a sapphire substrate with an atomic-scale flat surface; (2) a transition metal salt solution is loaded on the atomic-scale flat surface of the sapphire substrate obtained in the step (1), and secondary annealing treatment is carried out to obtain a sapphire substrate loaded with a monodisperse transition metal source; and (3) the transition metal chalcogenide is grown on the sapphire substrate loaded with the monodisperse transition metal source through a chemical vapor deposition method. A two-dimensional material prepared by the method is an absolute single layer, batch preparation on wafer-level (two inches, four inches, eight inches and twelve inches) sapphire substrates can be realized, the crystal quality is high, the single crystal size is large, the operation is simple, the cost is low, and industrialization is easy.

The invention discloses a two-sided grinding machine and a two-sided grinding method, and belongs to the technical field of grinding processes. The two-sided grinding machine comprises an upper grinding plate, a lower grinding plate, a planet wheel, a sun wheel, an external gear, a first drive device and a second drive device, wherein an inner gear ring is arranged on the edge of the sun wheel; anouter gear ring is arranged on the edge of the external gear; the planet wheel meshes with the inner gear ring and the outer gear ring; the first drive device is in transmission connection with the sun wheel; the second drive device is in transmission connection with the external gear; and the two-sided grinding machine is alternately at a first state and a second state when being used for grinding a sapphire substrate, the rotate speed of at least one of the first drive device and the second drive device at the first state is different from the rotate speed of at least one of the first drivedevice and the second drive device at the second state, and the total wearing capacity of the meshing part of the planet wheel and the inner gear ring in the lower grinding plate at the first state and the second state is equal to the total wearing capacity of the meshing part of the planet wheel and the outer gear ring in the lower grinding plate at the first state and the second state. According to the two-sided grinding machine and the two-sided grinding method provided by the invention, the surface smoothness of the lower grinding plate can be improved.

The invention discloses a graphite disc turnover type GaN single crystal substrate laser pre-stripping integrated cavity. A heat preservation tray containing a phase change material is adopted to achieve heat preservation of a graphite disc, the temperature of the heat preservation tray can be kept at 700 DEG C or above within a certain period of time, the probability of growth quality problems caused by sudden temperature change or too low temperature of a GaN single crystal substrate slice is remarkably reduced, and the growth quality of GaN single crystals is improved; the integrated chamber is connected with the HVPE equipment, a certain vacuum degree or inert gas filling can be achieved in the chamber, the heating and heat preservation functions are achieved, the environment atmosphere of the GaN single crystal substrate slice in the whole transfer process can be guaranteed, and the growth quality of the GaN single crystal substrate in the subsequent process is guaranteed; the transfer tray with the heat preservation function is adopted to transfer the GaN single crystal substrate slices in the heat preservation tray in the integrated cavity in a full-disc mode, the sapphire substrate faces of all the GaN single crystal wafers face upwards, and therefore the Bernoulli adsorption transmission mode can be canceled, and the laser pre-stripping efficiency of the GaN single crystal substrate slices can be remarkably improved.

The invention relates to an electrical fire monitoring system and particularly relates to an electrical fire monitoring system based on a photoelectric thin film chip. The system is composed of an alpha-Ga2O3/beta-Ga2O3 phase junction thin film chip, an electric spark photoelectric detection peripheral circuit, a buzzer and a network communication module, wherein the alpha-Ga2O3/beta-Ga2O3 phase-junction thin film chip comprises an alpha-Ga2O3 thin film, a beta-Ga2O3 thin film, a Ti/Au thin film electrode and a sapphire substrate, the alpha-Ga2O3 thin film is arranged above the beta-Ga2O3 thinfilm, the thickness is 200 to 300nm, the thickness of the beta-Ga2O3 thin film ranges from 200 nm to 300 nm, an alpha-Ga2O3/beta-Ga2O3 phase junction thin film chip is formed, the sapphire substrateis used as a substrate for preparing the beta-Ga2O3 thin film, the area of the alpha-Ga2O3 thin film is half of the area of the beta-Ga2O3 thin film, the Ti/Au thin film electrode is located on a surface of the alpha-Ga2O3 thin film and a surface of the beta-Ga2O3 thin film, the shape of the Ti/Au thin film electrode is a square with the side length of 2.0 mm, the thickness of the Ti thin film electrode is 20-30 nm, the Au thin film electrode is located above the Ti thin film electrode, and the thickness of the Au thin film electrode is 60-90 nm. The electrical fire monitoring system is advantaged in that the electrical fire monitoring system can realize remote monitoring and alarming, and can be applied to remote electrical fire alarming and high-voltage transmission line corona monitoring.