45results about How to "Increased radiative recombination rate" patented technology

The invention discloses an ultraviolet LED epitaxial structure, which comprises a substrate, a buffer layer, an n-type AlGaN layer, a multi-quantum well region, a composite structure region and a p-type GaN layer arranged in turn from bottom to top. The composite structure region is composed of an Al<x>Ga<1-x>N concave layer, a p-type Al<y>Ga<1-y>N electron barrier layer and a p-type Al<z>Ga<1-z>Nhole injection layer in turn from bottom to top. By adjusting the Al components of all parts of AlGaN of the composite structure region individually or jointly, the composite structure region obtained not only can reduce the electron leakage in the multi-quantum well region, but also can increase hole injection. The epitaxial structure provided by the invention can enhance radiation recombinationand improve the optical output power of ultraviolet LED.

The invention provides a deep ultraviolet LED epitaxial structure, a preparation method thereof, and a deep ultraviolet LED. The deep ultraviolet LED epitaxial structure comprises a substrate, a buffer layer, an N-type AlGaN layer, a multi-quantum well structure, an electron barrier layer, a P-type AlGaN layer and a P-type GaN layer, wherein the buffer layer, the N-type AlGaN layer, the multi-quantum well structure, the electron barrier layer, the P-type AlGaN layer and the P-type GaN layer are sequentially laminated upwards from the substrate. The P-type AlGaN layer comprises a first sub-layer, a second sub-layer and a third sub-layer, wherein the first sub-layer is P-type Al<x>Ga<1-x>N layer; the second sub-layer comprises non-doped Al<y>Ga<1-y>N layers and doped Al<y>Ga<1-y>N layers, which are stacked alternately, wherein the number of alternation times is greater than or equal to 1; the third sub-layer is P-type Al<z>Ga<1-z>N layer, wherein 1>x>y>z>0. According to the deep ultraviolet LED epitaxial structure provided by the invention, the luminous efficiency and the internal quantum efficiency of the ultraviolet LED are improved by changing the structure of the P-type AlGaN layer, so that the performance of the ultraviolet LED is improved.

The invention discloses a ZnO-based nanorod / quantum well composite ultraviolet light-emitting diode and a preparation method thereof. The light-emitting diode comprises a substrate. The substrate is provided with an n-type ZnO thin film layer, a ZnO nanorod array, a ZnO / Zn1-xMgxO quantum well active layer, a p-type NiO thin film layer and a first electrode from the bottom up in sequence. A second electrode and the ZnO nanorod array are arranged on the n-type ZnO thin film layer in parallel; and the ZnO / Zn1-xMgxO quantum well active layer covers the ZnO nanorod array, 0.1<=x<=0.3. The light-emitting diode electroluminescent peak wavelength is around 374 nm, and full width at half maximum of the photoluminescence peak is around 17 nm; the light-emitting diode structure can give full play to the advantages of direct broadband gap and high exciton binding energy of the ZnO material and the like, so that polarization effect is reduced effectively, material and interface quality can be improved, effective area of the active layer is increased, light extraction efficiency is improved and spectrum monochromaticity is improved; and besides, low-temperature preparation can be realized, cost is low and industrialization can be realized easily.

The invention discloses a gallium nitride-based light-emitting diode epitaxial wafer and a manufacturing method thereof, and belongs to the technical field of semiconductors. A multi-quantum-well layer of the gallium nitride-based light-emitting diode epitaxial wafer comprises a plurality of quantum well layers and quantum barrier layers, wherein the quantum well layers and the quantum barrier layers are alternately grown, and each quantum well layer comprises a plurality of layers of InxGa1-xN quantum well sub-layers, wherein the In content in the plurality of layers of quantum well sub-layers is gradually increased and then gradually decreased layer by layer along the stacking direction of the epitaxial wafer; each quantum barrier layer comprises multiple layers of Si-doped ByGa1-yN quantum barrier sub-layers, wherein the B content in the plurality of layers of quantum barrier sub-layers is gradually increased and then gradually decreased layer by layer along the stacking direction of the epitaxial wafer; and x is greater than or equal to 0 and less than or equal to 1, and y is more than or equal to 0 and less than or equal to 1. According to the gallium nitride-based light-emitting diode epitaxial wafer provided by the invention, the distribution uniformity of electrons in the quantum wells can be improved, so that the radiation recombination rate of electrons and holes in the multi-quantum wells is improved, and the luminous efficiency of the LED is further improved.

The invention discloses a light-emitting diode epitaxial wafer and a preparation method thereof, and belongs to the technical field of semiconductors. The epitaxial wafer includes a substrate, a buffer layer, an N-type semiconductor layer, an active layer, and a P-type semiconductor layer, wherein the buffer layer, the N-type semiconductor layer, the active layer and the P-type semiconductor layerare stacked on the substrate. The active layer comprises n quantum wells and (n+1) quantum barriers, wherein n is an integer which is not less than two. The n quantum wells and (n+1) quantum barriersare alternately stacked, and each quantum well is an indium gallium nitride layer. The quantum barrier which is the closest to the N-type semiconductor layer is a gallium nitride layer, and all otherquantum barriers are of composite structures. The composite structures of the quantum barriers between all adjacent quantum wells each include a first sub-layer, a second sub-layer, a third sub-layer, a fourth sub-layer and a fifth sub-layer, wherein the first sub-layer and the fifth sub-layer are gallium nitride layers, the second sub-layer is an aluminum gallium nitride layer, and the third sub-layer is an N-type doped gallium nitride layer, and the fourth sub-layer is an indium gallium nitride layer. The epitaxial wafer can improve the luminous efficiency of an LED.

The invention discloses an Si-substrate LED epitaxial wafer and a preparation method therefor, and relates to the technical fields of a device with a special crystal structure and a preparation method for the device. The epitaxial wafer comprises an Si substrate and an epitaxial layer positioned on the surface of the Si substrate; and the epitaxial layer comprises an AlN / AlGaN buffer layer, an non-intentional-doped U-shaped GaN layer, an Si-doped N type GaN layer, an InGaN / Gan multiple-quantum well luminous layer, an electronic battier layer and an Mg-doped P type GaN layer from the bottom up in sequence. According to the epitaxial wafer, the internal quantum efficiency is improved, the piezoelectric polarization electric field is reduced and the wave function alternation of electrons and holes is increased, so that the radiation recombination probability is improved, and the internal quantum efficiency is further improved.

The invention discloses a GaN LED epitaxial structure and a growth method thereof, which sequentially include processing a substrate, growing a low-temperature nucleation layer, growing a non-doped low-temperature u-GaN layer, growing a Si-doped n-GaN layer, and growing a light-emitting layer , growing a GaN-AlGaN-GaN barrier layer, growing a P-type GaN layer, and cooling down. The present invention adopts the GaN-AlGaN-GaN combined structure, which can effectively provide electron potential barriers to limit the leakage of electrons to the P-type region, reduce the non-radiative recombination of electrons and holes in the P-type region, and effectively improve the efficiency of the holes. The implantation from the P electrode to the active area improves the optoelectronic performance of the device; the removal of the traditional AlGaN electron blocking layer avoids serious lattice defects at the material interface when growing a thicker and highly Mg-doped p-type AlGaN layer And the problem of large stress, it also avoids the influence of long-term high-temperature growth on the MQW layer, and improves the chip quality.

The invention discloses a gallium nitride-based light-emitting diode epitaxial wafer and a manufacturing method thereof, belonging to the technical field of semiconductors. The gallium nitride-based light-emitting diode epitaxial wafer includes an insertion layer arranged between the multi-quantum well layer and the electron blocking layer, and the insertion layer includes a plurality of periodic superlattice structures, and each superlattice Each structure includes a first sublayer and a second sublayer disposed on the first sublayer, the first sublayer is a BInN layer, and the second sublayer is a BAlN layer. By setting the insertion layer, the phenomenon of downward bending of the energy band of the electron blocking layer caused by lattice mismatch between the last GaN barrier layer and the electron blocking layer of the multi-quantum well layer can be improved, and the radiative recombination rate of electrons and holes can be improved. Ultimately improve the luminous efficiency of LED.

The invention belongs to the field of photoelectronic devices, specifically a method for improving the light-emitting efficiency of an LED based on the 3D printing of a ferromagnetic layer. The method employs an MOCVD or MBE growth epitaxial wafer which is provided with a nucleating layer, an unintentionally doped layer, an n-type layer, a multi-cycle quantum well active layer and a p-type layer, etches an n-type layer table surface, and carries out 3D printing of an ohmic contact reflector, an n-type electrode, a p-type electrode, a ferromagnetic material layer, and a ferromagnetic material protection layer. The method improves the light-emitting efficiency of the LED through employing the 3D printing of the ferromagnetic layer. A magnetic field generated by the ferromagnetic material layer acts on a multi-quantum-well active region, can enable carriers to be limited in an In-abundant region, and improves the radiative recombination rate of carriers, thereby improving the light-emitting efficiency. Moreover, the 3D printing is simple in production process, and can effectively improve the production efficiency.