37results about How to "Improved current spread" patented technology

The invention provides the epitaxial device of a semiconductor light emitting diode. The device comprises an N electrode, an N-type semiconductor contact layer, an N-type semiconductor conducting layer, a luminescent layer, a P-type semiconductor conducting layer, a P-type semiconductor contact layer and a P electrode which are successively contacted with each other. An interface contact resistance between the N electrode and the N-type semiconductor contact layer is adjusted by the doping concentration of the N-type semiconductor contact layer. Or an interface contact resistance between the Pelectrode and the P-type semiconductor contact layer is adjusted by the doping concentration of the P-type semiconductor contact layer. In the invention, in an interface where the surface of a semiconductor is contacted with a metal electrode, current expansion is improved; because the contact of metal and the semiconductor is sensitive, the electric conductivity of the interface is easy to adjust and control, and only a thin layer is needed in an epitaxy so that the current expansion can be greatly improved; and the ascending range of a device voltage is small.

The disclosure provides an epitaxial wafer of an ultraviolet light-emitting diode and a preparation method thereof, belonging to the field of light-emitting diodes. The epitaxial wafer includes: a substrate and a low-temperature buffer layer sequentially stacked on the substrate, a first undoped AlGaN layer, an N-type semiconductor layer, an active layer, and a P-type semiconductor layer, and the N-type semiconductor layer including a highly doped N-type layer and a low-doped N-type layer sequentially stacked on the first undoped AlGaN layer, and the low-doped N-type layer includes stacking on the highly doped N-type layer The first low-doped layer, the highly-doped N-type layer and the first low-doped layer both include a plurality of AlGaN layers and a plurality of SiN layers alternately distributed, and Si in the highly-doped N-type layer The doping concentration is higher than the Si doping concentration in the low-doped N-type layer. The present disclosure can improve the electrical performance of the ultraviolet light emitting diode.

This invention discloses one semiconductor light element and its process method, which The device has upper and down electrode structure through device light layer both sides two ohm electrodes relative space upper shape compensation or etching block light down part of semiconductor to reduce upper and down light parts current crowding situations.

The invention provides a vertical GaN-based LED chip and a manufacture method thereof. The chip comprises a substrate, N type GaN, a quantum well active layer, P type GaN, a current expansion layer, a metal mirror and a conductive substrate; a P electrode is manufactured on the conductive substrate; a window directly toward a N type GaN layer is arranged on the substrate; a layer of metal is evaporated at each side in the window; a N electrode is led out from the metal layer. The manufacture method comprises the following steps: epitaxially growing the N type GaN, the quantum well active layer, the P type GaN and the current expansion layer on a sapphire or 6H-SiC transparent substrate from bottom to top in sequence according to the conventional method; the metal mirror is manufactured onthe current expansion layer; the conductive substrate is welded on the metal mirror; the window directly toward the N type GaN layer is processed; the metal layer is evaporated at each side in the window and the N electrode is led out from the metal layer. The invention reduces the influence of instable factors in the technological process. The GaN-based LED chip is high in utilization ratio of effective light-emitting area, good in current expansion and good in heat dissipation of tube cores.

The invention discloses a III-group nitride light-emitting diode (LED) and a manufacturing method thereof. The LED comprises a substrate and a semiconductor epitaxial laminate which is laminated on the substrate, wherein the semiconductor epitaxial laminate sequentially comprises an N type layer, a luminescent layer and a P type layer from top to bottom. The LED is characterized in that: an N type layer table face is formed in the N type layer by etching a part of the semiconductor epitaxial laminate; an N type electrode is arranged on the N type layer table face; a P type electrode is arranged on the upper surface of the un-etched part of the P type layer; the N type layer also comprises a uniformly doped layer of which the doping concentration is consistent and a modulation doped layer of which the doping concentration is changeable; and the modulation doped layer is arranged between the uniformly doped layer and the luminescent layer. A doped mode of the modulation doped layer is gradual transition doping which connects uniformly doped layer and the luminescent layer of which the doping concentration is consistent. The concentration change trend is decrease progressively change from the uniformly doped layer to the luminescent layer. By the LED and the manufacturing method, the crystal quality and the luminance uniformity can be obviously improved, and the lighting effect is improved.

The invention discloses a high-brightness light-emitting diode based on an AIN / PSS composite substrate and a preparation method of the high-brightness light-emitting diode. The high-brightness light-emitting diode comprises the AlN / PSS composite substrate, a u-type GaN merging layer, an n-type GaN layer, a low-temperature GaN V-pits layer, an active region, an electron blocking layer, a high-temperature p-type GaN layer and a contact layer which are sequentially stacked from bottom to top. The high-brightness light-emitting diode provided by the invention comprises the u-GaN merging layer of anovel structure, the V-pits layer and the active region; and therefore, the crystal quality of an epitaxial layer can be effectively improved, the stress of the active region can be effectively relieved, current expansion in a horizontal direction can be improved, the light-emitting efficiency of the light-emitting diode can be improved, and the brightness of the prepared light-emitting diode ishigh.

A reverse polarity vertical light emitting diode and its preparation method, the reverse polarity vertical light emitting diode comprises: a substrate; an n-type electrode located on the substrate; an n-type GaN-based semiconductor layer located on the n-type electrode the light-emitting layer is located on the n-type GaN-based semiconductor layer; the p-type GaN-based semiconductor layer is located on the light-emitting layer; the p-type electrode is located on the p-type GaN-based semiconductor layer; The n-type GaN-based semiconductor layer, light-emitting layer and p-type GaN-based semiconductor layer all show nitrogen polarity in the bottom-up direction, and show metal polarity in the top-down direction. The present invention integrates the advantages of reverse polarity and vertical structure, can effectively increase the hole concentration of the p-type GaN-based semiconductor layer, suppress the quantum-confined Stark effect in the active region of the quantum well, thereby improving the radiation recombination efficiency and internal quantum of the LED Efficiency, improving the luminous performance and reliability of LEDs.

The invention provides a transparent electrode of a light-emitting diode. A preparation method of the transparent electrode comprises the following steps: S1, carrying out chemical cleaning on the surface of an epitaxial wafer, then putting the epitaxial wafer into an MOCVD reaction chamber with temperature of 300-900 DEG C and pressure of 3-100 Torr, and treating for 1-60 minutes; S2, under the protective atmosphere, adjusting the growth temperature to 450-650 DEG C, adjusting the pressure of the reaction chamber to 3-80 Torr, then, introducing an indium source, a tin source and an oxygen source, controlling the growth speed to 0.1-3 nm / min, and growing an ITO main body layer with the thickness of 40-500 nm on the surface of the pretreated epitaxial wafer; and S3, under the protective atmosphere, adjusting the growth temperature to 300-450 DEG C, adjusting the pressure of the reaction chamber to 3-80 Torr, then, introducing an indium source, a tin source and an oxygen source, controlling the growth speed to 1-10 nm / min, and growing an ITO coarsening layer with the thickness of 20-200 nm on the ITO main body layer. The method for in-situ growth of the coarsening layer is very matched with the preparation method of a main body layer of the ITO transparent electrode, subsequent complex process treatment is avoided, and the light extraction efficiency of the LED can be effectivelyimproved.

The invention discloses a light emitting diode epitaxial wafer and a preparation method thereof, and belongs to the technical field of semiconductors. The light-emitting diode epitaxial wafer comprises a substrate, an N-type semiconductor layer, a stress release layer, an active layer and a P-type semiconductor layer, wherein the N-type semiconductor layer, the stress release layer, the active layer and the P-type semiconductor layer are sequentially stacked on the substrate; the stress release layer comprises a plurality of composite structures which are stacked in sequence, wherein each composite structure comprises a first sub-layer, a second sub-layer, a third sub-layer and a fourth sub-layer which are stacked in sequence; the first sub-layer is made of non-doped indium gallium nitride, the second sub-layer is made of non-doped aluminum nitride, the third sub-layer is made of silicon nitride, and the fourth sub-layer is made of non-doped gallium nitride. According to the light-emitting diode epitaxial wafer, the photoelectric property of the LED is finally improved.

The invention discloses a microcavity Micro-LED with a vertical structure for emitting circularly polarized light facing 3D display and a preparation method thereof. The microcavity Micro-LED of the present invention can emit circularly polarized light and use circularly polarized light for 3D polarized light display , as long as the optical axis position of the circularly polarized glasses is set properly, the crosstalk problem of the pattern caused by the tilt of the glasses can be eliminated. The present invention reduces the thickness of the chip, and uses the grating on the conductive layer and the dielectric film mirror on the n-GaN layer as the end face of the resonant cavity to form a resonant microcavity structure in the vertical direction, which will suppress the light from the side wall and improve the direction of light from the front sex. At the same time, the resonant microcavity structure will select a specific wavelength to narrow the emission spectrum and have higher spectral purity, which will help increase the threshold value of Micro-LED display. Moreover, the grating has polarization selective light output, and the output light through this structure is linearly polarized light. The top integrated micro-nano structure is equivalent to a 1 / 4 wave plate, which converts linearly polarized light into circularly polarized light.

The invention provides an epitaxial method for improving GaN based LED chip current spreading. An epitaxial structure comprises a sapphire substrate, a low-temperature GaN nucleating layer, a high-temperature GaN buffer layer, a high-temperature u-type GaN layer, a composite n-type GaN layer, a composite current spreading layer, a multi-quantum well light-emitting layer, a p-type AlGaN electron blocking layer, a high-temperature p-type GaN layer and a p-type GaN contact layer from bottom to top in sequence. After the composite n-type GaN layer finishes growing, the composite current spreading layer grows; the composite current spreading layer is composed of 15-20 groups of u-GaN / n-GaN superlattices and 5-10 groups of n-GaN / n-AlGaN superlattices. Current spreading of a prolate chip can be improved remarkably, local junction temperature of the chip is lowered, uniformity of light-emitting brightness distribution of the chip is improved, and the whole chip is uniform in light emission without brightness gathering.

The invention discloses a vertical high-voltage light-emitting diode chip and a manufacturing method thereof, wherein. Through the design of the vertical high voltage light emitting diode chip, the back electrode at the first chip area is electrically connected to the conductive substrate through the opening and the bonding layer, so that the back electrode is exposed without etching in the first chip area, so as to ensure the vertical high voltage light emitting diode. The effective light-emitting area of ​​the chip is large; and, the back electrode of the first chip area does not need to be wired, which saves costs and improves reliability; in addition, the current expansion of each chip area is in the vertical direction, and the first chip area The back electrode and the front electrode of the Nth chip area form a vertical structure, so that the current of the vertical high-voltage light-emitting diode chip expands better, thereby avoiding current congestion and improving the current tolerance; in addition, the vertical high-voltage light-emitting diode chip has a better light type , which conforms to the Lambertian distribution and is easier to light distribution.