Abstract: A light-emitting device includes a light-emitting laminating structure having an ohmic contact layer, a transition layer, a current-spreading layer, a first type semiconductor layer, an active layer, and a second type semiconductor layer. The current-spreading layer has aluminum, and, in the current-spreading layer, a relative content of the aluminum with respect to a composition of the current-spreading layer is fixed. The transition layer has aluminum, and, in the transition layer, a relative content of the aluminum with respect to a composition of the transition layer is less than the relative content of the aluminum in the current-spreading layer. A method for producing the light-emitting device is also disclosed.

Abstract: A multi-junction light-emitting diode (LED) includes a first epitaxial structure, a second epitaxial structure and a tunnel junction structure disposed therebetween. The tunnel junction structure includes a InzAlX1Ga1?X1As highly doped p-type semiconductor layer wherein z ranges from 0 to 0.05, a AlX2Ga1?X2As first composition graded layer wherein X2 is greater than 0 and less than X1, a GaYIn1?YP highly doped n-type semiconductor layer and a AlX3Ga1?X3As second composition graded layer that are sequentially disposed on the first epitaxial structure in such order. A method for making the abovementioned multi-junction LED is also disclosed.

Abstract: An AlGaInP light-emitting diode includes from bottom up a substrate, a distributed Bragg reflector (DBR) reflecting layer, an N-type semiconductor layer, a quantum well light-emitting layer, a P-type semiconductor layer, a transient layer and a P-type current spreading layer. The DBR reflecting layer is multispectral-doping. The P-type semiconductor layer includes a first P-type semiconductor layer adjacent to the quantum well light-emitting layer and a second P-type semiconductor layer adjacent to the transient layer. A doping concentration of the second P-type semiconductor layer is lower than that of the first P-type semiconductor layer. By improving doping concentration of the multispectral DBR reflecting layer, current spreading can be improved, thus improving aging performance. A concentration difference is formed with the transient layer to balance doping of the transient layer; this avoids increasing non-radiation composition from high doping of the transient layer during long-time aging.

Abstract: A high-brightness light-emitting diode with surface microstructure and preparation and screening methods thereof are provided. The ratio of total roughened surface area of light transmission surface of a light emitting diode to vertically projected area is greater than 1.5, and the peak density of light transmission surface is not less than 0.3/um2. The higher the ratio of total roughened surface area of an epitaxial wafer to vertically projected area and the higher the number of peak over the critical height within a unit area, the more beneficial to improve light extraction efficiency of the epitaxial wafer. As a result, light extraction efficiency of the epitaxial wafer is greatly improved.

Abstract: A four-element light emitting diode with a transparent substrate, comprising a AlGaInP light emitting diode (LED) epitaxial wafer, and the surface of a GaP layer of the AlGaInP-LED epitaxial wafer is roughened into a bonding surface, a film is plated on the bonding surface and is bonded with a transparent substrate, and finally a GaAs substrate is removed. The transparent bonding disclosed herein can replace the GaAs substrate made of light absorption materials with the transparent substrate by substrate transfer technology, increasing the light emitting efficiency of the light emitting diode chip and avoiding extremely low external quantum efficiency caused due to the limitations of the material of conventional AlGaInP light emitting diode and the substrate; in addition, with the support of the cut path pre-etching technology, back melting or splashing during the epitaxial layer cutting process is avoided, light emitting efficiency is increased and electric leakage risk is eliminated.

Abstract: An AlGaInP light-emitting diode includes from bottom up a substrate, a DBR reflecting layer, an N-type semiconductor layer, a quantum well light-emitting layer, a P-type semiconductor layer, a transient layer and a P-type current spreading layer. The DBR reflecting layer is multispectral-doping. The P-type semiconductor layer includes a first P-type semiconductor layer adjacent to the quantum well light-emitting layer and a second P-type semiconductor layer adjacent to the transient layer. A doping concentration of the second P-type semiconductor layer is lower than that of the first P-type semiconductor layer. By improving doping concentration of the multispectral DBR reflecting layer, current spreading can be improved, thus improving aging performance. A concentration difference is formed with the transient layer to balance doping of the transient layer; this avoids increasing non-radiation composition from high doping of the transient layer during long-time aging.

Abstract: A four-element light emitting diode with a transparent substrate, comprising a AlGaInP light emitting diode (LED) epitaxial wafer, and the surface of a GaP layer of the AlGaInP-LED epitaxial wafer is roughened into a bonding surface, a film is plated on the bonding surface and is bonded with a transparent substrate, and finally a GaAs substrate is removed. The transparent bonding disclosed herein can replace the GaAs substrate made of light absorption materials with the transparent substrate by substrate transfer technology, increasing the light emitting efficiency of the light emitting diode chip and avoiding extremely low external quantum efficiency caused due to the limitations of the material of conventional AlGaInP light emitting diode and the substrate; in addition, with the support of the cut path pre-etching technology, back melting or splashing during the epitaxial layer cutting process is avoided, light emitting efficiency is increased and electric leakage risk is eliminated.

Abstract: A high-brightness light-emitting diode with surface microstructure and preparation and screening methods thereof are provided. The ratio of total roughened surface area of light transmission surface of a light emitting diode to vertically projected area is greater than 1.5, and the peak density of light transmission surface is not less than 0.3/um2. The higher the ratio of total roughened surface area of an epitaxial wafer to vertically projected area and the higher the number of peak over the critical height within a unit area, the more beneficial to improve light extraction efficiency of the epitaxial wafer. As a result, light extraction efficiency of the epitaxial wafer is greatly improved.