Abstract: A light emitting diode comprising a multiple quantum well (MQW) layer as an active layer and a reflecting layer below the active layer, wherein the number and/or total thickness of well layers in the MQW layer is determined such that the MQW layer shows an external quantum efficiency higher than that of an MQW layer including a single well layer.

Abstract: A light-emitting diode having an excellent high-speed response characteristic and capable of giving a large light output with a small variation of the light output during the operation is provided. In the light-emitting diode, an active layer comprising a single quantum well layer of p-type Ga0.51In0.49P, a lower barrier layer of p-type (Al0.5Ga0.5)0.51In0.49P and an upper barrier layer of p-type (Al0.5Ga0.5)0.51In0.49P is highly doped with p-type dopant (Zn, Mg, Be, C) or n-type dopant (Si, Se, Te) to produce non-radiative recombination level in the upper and lower barrier layers. Carriers injected into the quantum well layer not only recombine radiatively therein and also recombine nonradiatively at boundaries of the upper barrier layer and the lower barrier layer, remarkably increasing recombination velocity of carriers and dramatically improving the response characteristic.

Abstract: The present invention relates to a semiconductor light-emitting device used for optical transmission (particularly for IEEE 1394) and displays and the like. More specifically, an object of the present invention is to provide a semiconductor light-emitting device capable of emitting the light with a high efficiency by extending a distance from an active layer to a boundary having poor crystal quality due to Group V elements As and P exchange to suppress deterioration in crystal quality of the active layer.

Abstract: A semiconductor light emitting device has in sequence on a semiconductor substrate, a multilayer reflection film, a semiconductor layer, and a quantum well active layer. A distance between an upper surface of the multilayer reflection film and a lower surface of the quantum well active layer is 2&lgr;/n or less, where &lgr; is a light emission wavelength and n is an average refractive index of the semiconductor layer disposed in between the multilayer reflection film and the quantum well active layer. A phase difference between a reflected ray of light reflected by the multilayer reflection film and an emitted ray of light from the quantum well active layer is a multiple of 2&pgr;. In an emission spectrum of the semiconductor light emitting device, two troughs caused by interference between the emitted ray of light and the reflected ray of light appear in the both sides of a main peak.

Abstract: A light emitting diode (LED) of a double hetero-junction type has a light-emitting layer of a GaAlInP material, a p-type cladding layer and an n-type cladding layer sandwiching the light-emitting layer therebetween, a p-side electrode formed on the p-type cladding layer side, and an n-side electrode formed on the n-type cladding layer side. The p-type cladding layer consists of a first p-type cladding layer positioned closer to the light-emitting layer and having a lower aluminum content and a lower impurity concentration, and a second p-type cladding layer positioned less closer to the light-emitting layer and having a higher aluminum content and a higher impurity concentration. The LED also has a current blocking layer below the p-side electrode for locally blocking electric current flowing from the p-side electrode to the n-side electrode.

Abstract: On an n-GaP substrate transparent against a radiation light of an InAlGaP based semiconductor element, a lattice distortion relaxation layer, a clad layer 13, an active layer, and a clad layer are created with InAlGaP. On top of the layers, there is formed an InxGa1-xP current diffusion layer with In composition ratio x equal to (0<X<1). Through these steps, uneven depth on the crystal surface is decreased and crystal defect concentration is lowered. In addition, the energy gap of the current diffusion layer is made larger than the energy gap of the active layer, so that the GaP substrate and the uppermost InGaP current diffusion layer become transparent against a radiation light from the active layer, resulting in increased light emitting efficiency. Further, simple formation of layers from the lattice distortion relaxation layer to the current diffusion layer in sequence enables reduction of the production costs.

Abstract: On a GaAs substrate (1), are formed a DBR (Distributed Bragg Reflector) (3), and a light-emitting layer (5) made of a plurality of layers of AlyGazIn1-y-zP (0≦y≦1, 0≦z≦1) above the DBR (3). A semiconductor layer or a plurality of semiconductor layers (6)-(10) having a number of layers of 1 or more are formed on the light-emitting layer (5), and a grating pattern for scattering light is formed on a surface of the semiconductor layer (9) by photolithography and by etching with a sulfuric acid/hydrogen peroxide based etchant. Thus, a semiconductor device small in radiation angle dependence of light emission wavelength, as well as a manufacturing method therefor, are provided.

Abstract: A light emitting diode includes a substrate, a light emitting layer, a first cladding layer having a first conductivity type and an energy gap greater than an energy gap of the light emitting layer, a second cladding layer having a second conductivity type and an energy gap greater than an energy gap of the light emitting layer, and an intermediate barrier layer having the same conductivity type as the conductivity type of the light emitting layer but different from the conductivity type of the first or second cladding layer, and having an energy gap less than the energy gap of the first or second cladding layer but greater than the energy gap of the light emitting layer. The light emitting diode has a double heterostructure such that the light emitting layer is interposed between the first and second cladding layer. The intermediate barrier layer is disposed between the light emitting layer and the first cladding layer and/or between the light emitting layer and the second cladding layer.

Abstract: The light-emitting diode array of the invention includes: a semiconductor substrate of a first conductivity type and a plurality of light-emitting elements linearly arranged on the substrate of the first conductivity type. Each of the plurality of light-emitting elements includes: a cladding layer of the first conductivity type; a cladding layer of a second conductivity type; an (AlxGa1−x)yIn1−yP (where 0≦x≦1 and 0≦y≦1) active layer interposed between the cladding layer of the first conductivity type and the cladding layer of the second conductivity type; and a current diffusion layer of the second conductivity type deposited on the cladding layer of the second conductivity type. In the light-emitting diode array, at least the current diffusion layer of the second conductivity type and the cladding layer of the second conductivity type are electrically isolated from each other in two adjacent light-emitting elements among the plurality of light-emitting elements.

Abstract: According to a light emitting diode fabricating method, when a top surface of an n-type GaAs substrate is inclined at an angle .theta. with respect to a (1 0 0) plane, a front electrode is formed on a surface shaped portion of a current diffusing layer of a thickness of `d`, the surface shaped portion reflecting a shape of a current blocking portion, in a displaced manner by an amount of approximately d/tan .theta. from in a direction opposite to a direction in which the surface shaped portion has been displaced with respect to the current blocking portion. Thus, the front electrode is formed in a correct position over the current blocking portion.

Abstract: A method for producing a light-emitting diode includes the steps of: forming a single-layered or multi-layered Al.sub.x Ga.sub.y In.sub.1-x-y P (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) light-emitting layer, an Al.sub.x Ga.sub.y In.sub.1-x-y P (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) intermediate layer of a second conductivity type, and an Al.sub.x Ga.sub.y In.sub.1-x-y P (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) current diffusion layer of a second conductivity type on a GaAs substrate of a first conductivity type; forming a first electrode of a first conductivity type and a second electrode of a second conductivity type so as to contact the GaAs substrate and the current diffusion layer, respectively; forming a protection film on exposed surfaces of the current diffusion layer and the second electrode; forming grooves by dicing so as to interpose the second electrode and to reach the GaAs substrate; etching the light-emitting layer, the intermediate layer, and the current diffusion layer by 4 .mu.