Abstract: A light emitting device including an emissive material comprising quantum dots is disclosed. In one embodiment, the device includes a cathode, a layer comprising a material capable of transporting and injection electrons comprising an inorganic material, an emissive layer comprising quantum dots, a layer comprising a material capable of transporting holes, a layer comprising a hole injection material, and an anode. In certain embodiments, the hole injection material can be a p-type doped hole transport material. In certain preferred embodiments, quantum dots comprise semiconductor nanocrystals. In another aspect of the invention, there is provided a light emitting device wherein the device has an initial turn-on voltage that is not greater than 1240/?, wherein ? represents the wavelength (nm) of light emitted by the emissive layer. Other light emitting devices and a method are disclosed.

Abstract: A method for fabricating a semiconductor light-emitting device includes fabricating a multilayer semiconductor structure on a first substrate, wherein the multilayer semiconductor structure comprises a first doped semiconductor layer, an MQW active layer, a second doped semiconductor layer, and a first passivation layer. The method further involves patterning and etching part of the first passivation layer to expose the first doped semiconductor layer. A first electrode is then formed, which is coupled to the first doped semiconductor layer. Next, the multilayer structure is bonded to a second substrate; and the first substrate is removed. A second electrode is formed, which is coupled to the second doped semiconductor layer. Further, a second passivation layer is formed, which substantially covers the sidewalls of multilayer structure and part of the surface of the second doped semiconductor layer which is not covered by the second electrode.

Abstract: A light emitting device according to the embodiment includes a support substrate; a reflective layer over the support substrate; an ohmic contact layer over the reflective layer; a light emitting semiconductor layer including a second conductive semiconductor layer, an active layer and a first conductive semiconductor layer over the ohmic contact layer; a first passivation layer surrounding a lateral side of the light emitting semiconductor layer; and a second passivation layer surrounding lateral sides of the first passivation layer and the reflective layer.

Abstract: Disclosed is a light emitting device. The light emitting device includes a first conductive semiconductor layer, an active layer over the first conductive semiconductor layer, a second conductive semiconductor layer over the active layer, a superlattice structure layer over the second conductive semiconductor layer, and a first current spreading layer including a transmissive conductive thin film over the superlattice structure layer.

Abstract: A method of manufacturing an optoelectronic light emitting semiconductor device is provided where a Multi-quantum Well (MQW) subassembly is subjected to reduced temperature vapor deposition processing to form one or more of n-type or p-type layers over the MQW subassembly utilizing a plurality of precursors and an indium surfactant. The precursors and the indium surfactant are introduced into the vapor deposition process at respective flow rates with the aid of one or more carrier gases, at least one of which comprises H2. The indium surfactant comprises an amount of indium sufficient to improve crystal quality of the p-type layers formed during the reduced temperature vapor deposition processing and the respective precursor flow rates and the H2 content of the carrier gas are selected to maintain a mole fraction of indium from the indium surfactant to be less than approximately 1% in the n-type or p-type layers.

Abstract: A semiconductor light-emitting device includes a substrate, a first doped semiconductor layer, a second doped semiconductor layer situated above the first doped semiconductor layer, and a multi-quantum-well (MQW) active layer situated between the first and the second doped layers. The device also includes a first electrode coupled to the first doped semiconductor layer, wherein part of the first doped semiconductor layer is passivated, and wherein the passivated portion of the first doped semiconductor layer substantially insulates the first electrode from the edges of the first doped semiconductor layer, thereby reducing surface recombination. The device further includes a second electrode coupled to the second doped semiconductor layer and a passivation layer which substantially covers the sidewalls of the first and second doped semiconductor layers, the MQW active layer, and part of the horizontal surface of the second doped semiconductor layer which is not covered by the second electrode.

Abstract: A light emitting device includes: a laminated body including a first conductivity type layer, a light emitting layer provided on the first conductivity type layer, and a second conductivity type layer provided on the light emitting layer, the laminated body being made of InxGayAl1-x-yN (0?x?1, 0?y?1, x+y?1); a first electrode provided on the first conductivity type layer exposed to a bottom surface of a step difference provided in the laminated body; a translucent electrode provided on one portion of an upper face of the second conductivity type layer; and a second electrode provided on the translucent electrode and being smaller than the translucent electrode. A length of the other portion of the upper face of the second conductivity layer between an end portion of the translucent electrode and the side face of the step difference is 30 ?m or more along a line connecting between a center of the first electrode and a center of the second electrode.

Abstract: Provided are a light emitting device and a light emitting device package including the same. The light emitting device comprises a first conductive type semiconductor layer, an active layer comprising a plurality of quantum well layers and a plurality of barrier layers, which are alternately laminated on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer. The plurality of barrier layers comprise a plurality of first barrier layers comprising a conductive type dopant, and the conductive type dopant doped into the plurality of first barrier layers have different doping concentrations for each layer.

Abstract: A double-metallic deposition process is used whereby adjacent layers of different metals are deposited on a substrate. The surface plasmon frequency of a base layer of a first metal is tuned by the surface plasmon frequency of a second layer of a second metal formed thereon. The amount of tuning is dependent upon the thickness of the metallic layers, and thus tuning can be achieved by varying the thicknesses of one or both of the metallic layers. In a preferred embodiment directed to enhanced LED technology in the green spectrum regime, a double-metallic Au/Ag layer comprising a base layer of gold (Au) followed by a second layer of silver (Ag) formed thereon is deposited on top of InGaN/GaN quantum wells (QWs) on a sapphire/GaN substrate.

Abstract: Some embodiments include formation of at least one cavity in a first semiconductor material, followed by epitaxially growing a second semiconductor material over the first semiconductor material and bridging across the at least one cavity. The cavity may be left open, or material may be provided within the cavity. The material provided within the cavity may be suitable for forming, for example, one or more of electromagnetic radiation interaction components, transistor gates, insulative structures, and coolant structures. Some embodiments include one or more of transistor devices, electromagnetic radiation interaction components, transistor devices, coolant structures, insulative structures and gas reservoirs.

Abstract: Example embodiments relate to a light emitting device and a method of fabricating the light emitting device. The light emitting device may include an n-type clad layer including a plurality of nitride semiconductor layers, at least one interlayer disposed between the plurality of nitride semiconductor layers, a via hole in which a first electrode is formed, a p-type clad layer, and an active layer between the n-type clad layer and the p-type clad layer.

Abstract: Amongst the candidates for very high efficiency solid state lights sources and full solar spectrum solar cells are devices based upon InGaN nanowires. Additionally these nanowires typically require heterostructures, quantum dots, etc which all place requirements for these structures to be grown with relatively few defects. Further manufacturing requirements demand reproducible nanowire diameter, length etc to allow these nanowires to be embedded within device structures. Additionally flexibility according to the device design requires that the nanowire at the substrate may be either InN or GaN. According to the invention a method of growing relatively defect free nanowires and associated structures for group III—nitrides is presented without the requirement for foreign metal catalysts and overcoming the non-uniform growth of prior art non-catalyst growth techniques. The technique also allows for unique dot-within-a-dot nanowire structures.

Abstract: A blue light emitting semiconductor nanocrystal having an quantum yield of greater than 20% can be incorporated in a light emitting device.

Abstract: A semiconductor device (1) and a method are disclosed for obtaining on a substrate (2) a multilayer structure (3) with a quantum well structure (4). The quantum well structure (4) comprises a semiconductor layer (5) sandwiched by insulating layers (6,6?), wherein the material of the insulating layers (6,6?) has preferably a high dielectric constant. In a FET the quantum wells (4,9) function as channels, allowing a higher drive current and a lower off current. Short channel effects are reduced. The multi-channel FET is suitable to operate even for sub-35 nm gate lengths. In the method the quantum wells are formed by epitaxial growth of the high dielectric constant material and the semiconductor material alternately on top of each other, preferably with MBE.

Abstract: There is provided a nitride semiconductor light emitting device including an active layer having enhanced external quantum efficiency at both low and high current density. The nitride semiconductor light emitting device includes a first conductivity type nitride semiconductor layer; an active layer disposed on the first conductivity type nitride semiconductor layer and having a plurality of quantum well layers and at least one quantum barrier layer alternately arranged; and a second conductivity type nitride semiconductor layer disposed on the active layer. The plurality of quantum well layers disposed adjacent to each other include first and second quantum well layers having different thicknesses.

Abstract: A light emitting device includes a substrate having a first surface and a second surface not parallel to the first surface, and a light emission layer disposed over the second surface to emit light. The light emission layer has a light emission surface which is not parallel to the first surface.

Abstract: A light emitting device may include a plurality of nano-structures having a strip shape, each including a first nano-structure and a second nano-structure, the first nano-structures being the same height on the buffer layer.

Abstract: The present invention provides a top emission type organic light-emitting display device in a production of which it is possible to prevent the organic film from being oxidized when the upper transparent electrode is formed, and which is capable of emitting light at a low voltage. This organic light-emitting display device contains an organic light-emitting layer and an upper electrode and a lower electrode sandwiching the organic light-emitting layer, and is of a structure in which the emitted light is taken out from the upper electrode side, and a buffer layer mainly made of an oxide producing less oxygen by decomposition in the film-forming process than the upper electrode material is provided between the organic light-emitting layer and the upper electrode.

Abstract: A light-emitting device includes a substrate, a first doped semiconductor layer situated above the substrate, a second doped semiconductor layer situated above the first doped layer, and a multi-quantum-well (MQW) active layer situated between the first and the second doped layers. The device also includes a first electrode coupled to the first doped layer and a first passivation layer situated between the first electrode and the first doped layer in areas other than an ohmic-contact area. The first passivation layer substantially insulates the first electrode from edges of the first doped layer, thereby reducing surface recombination. The device further includes a second electrode coupled to the second doped layer and a second passivation layer which substantially covers the sidewalls of the first and second doped layers, the MQW active layer, and the horizontal surface of the second doped layer.

Abstract: A semiconductor device includes a substrate comprising a first surface having a first orientation and a second surface having a second orientation and a plurality of III-V nitride layers on the substrate, wherein the plurality of III-V nitride layers are configured to emit light when an electric current is produced in one or more of the plurality of III-V nitride layers.

Abstract: A single chip type white light LED device includes a first semiconductor layer of a first doping type, a ZnMnSeTe (Zinc Manganese Selenium Tellurium) red light quantum well, a first barrier layer disposed on the ZnMnSeTe red light quantum well, a green light emitting layer including green light quantum dots disposed on the first barrier layer, a second barrier layer disposed on the green light emitting layer, a blue light emitting layer including blue light quantum dots disposed on the second barrier layer, a third barrier layer disposed on the blue light emitting layer, and a second semiconductor layer disposed on the third barrier layer.

Abstract: Methods of performing laser spike annealing (LSA) in forming gallium nitride (GaN) light-emitting diodes (LEDs) as well as GaN LEDs formed using LSA are disclosed. An exemplary method includes forming atop a substrate a GaN multilayer structure having a n-GaN layer and a p-GaN layer that sandwich an active layer. The method also includes performing LSA by scanning a laser beam over the p-GaN layer. The method further includes forming a transparent conducting layer atop the GaN multilayer structure, and adding a p-contact to the transparent conducting layer and a n-contact to the n-GaN layer. The resultant GaN LEDs have enhanced output power, lower turn-on voltage and reduced series resistance.

Abstract: A light emitting device with a coupled quantum well structure in an active region. The coupled quantum well structure may include two or more wells are separated by one or more mini-barriers, and the wells and mini-barriers together are sandwiched by barriers. The coupled quantum well structure provides almost the same effect as a wide quantum well, due to the coupling of the wavefunctions through the mini-barrier. The light emitting device may be a nonpolar, semipolar or polar (Al,Ga,In)N based light emitting device.

Abstract: The present invention provides an applications-oriented nitride compound semiconductor substrate, and devices based on it, whose lattice constant can be tuned to closely match that of any nitride thin film or films deposited on it for specific electronic or optoelectronic device applications. Such application-oriented nitride substrates, which can be composed of ternary InxGa1-xN, AlyIn1-yN, AlzGa1-zN, or quaternary AlaInbGa1-a-bN alloy compounds, minimize lattice-mismatch-induced dislocations and defects between the epitaxial films and the substrate on which the device layers are grown, leading to substantially improved device performance.

Abstract: Disclosed are a light emitting device and a method of manufacturing the same. The light emitting device includes a support substrate, a wafer bonding layer over the support substrate, a second electrode layer, which includes a current blocking layer and a reflective current spreading layer, over the wafer bonding layer, a current injection layer over the second electrode layer, a superlattice structure layer over the current injection layer, a second conductive semiconductor layer over the superlattice structure layer, an active layer over the second conductive semiconductor layer, a first conductive semiconductor layer over the active layer, and a first electrode layer over the first conductive semiconductor layer.

Abstract: A reflecting light emitting structure includes a substrate having a plurality of grooves formed in a first face of the substrate is disclosed. The first face is in a first crystallographic plane. Each of the plurality of grooves includes a first sidewall that is coplanar with a second crystallographic plane and a second sidewall that is coplanar with a third crystallographic plane. A buffer layer is provided on the substrate to reduce mechanical strain between the substrate and a light emitting diode (LED) fabricated on the buffer layer.

Abstract: In a method of manufacturing a vertical type light-emitting diode, a multilayered structure of group III nitride semiconductor compounds is epitaxy deposited on an irregular surface of a substrate. The substrate is then removed to expose an irregular surface of the multilayered structure corresponding to the irregular surface of the substrate. A portion of the exposed irregular surface of the multilayered structure is then etched for forming an electrode contact surface on which an electrode layer is subsequently formed. With this method, no specific planarized region is required on the irregular surface of the substrate. As a result, planarization treatment of the substrate is not necessary. The same substrate with the irregular surface can be reused for fabricating vertical and horizontal light-emitting diodes.

Abstract: A light emitting device, a method of manufacturing the same, a light emitting device package, and a lighting system are disclosed. The light emitting device may include a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer interposed between the first and second conductive semiconductor layers. The first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer may include Al. The second conductive semiconductor layer may have Al content higher than Al content of the first conductive semiconductor layer. The first conductive semiconductor layer may have Al content higher than Al content of the active layer.

Abstract: A nitride semiconductor light emitting device is provided with a substrate, an n-type nitride semiconductor layer, a p-type nitride semiconductor layer, an n-side pad electrode, a translucent electrode and a p-side pad electrode, wherein the translucent electrode is formed from an electrically conductive oxide, the n-side pad electrode adjoins the periphery of the translucent electrode and the p-side pad electrode is disposed so as to satisfy the following relationships: 0.3L?X?0.5L and 0.2L?Y?0.5L where X is the distance between ends of the p-side pad electrode and the n-side pad electrode, Y is the distance between the end of the p-side pad electrode and the periphery of the translucent electrode, L is the length of the translucent electrode on the line connecting the centroids of the p-side pad electrode and the n-side pad electrode minus the outer diameter d of the p-side pad electrode.

Abstract: Disclosed is a semiconductor light emitting device. The semiconductor light emitting device comprises a first conductive semiconductor layer, a lower super lattice layer under the first conductive semiconductor layer, an active layer on the first conductive semiconductor layer, a second conductive super lattice layer on the active layer, and a second conductive semiconductor layer on the second conductive super lattice layer.

Abstract: The present invention relates to flexible devices including semiconductor nanocrystals, arrays including such devices, systems including the foregoing, and related methods. In one embodiment, a flexible light-emitting device includes a flexible substrate including a first electrode, an emissive layer comprising semiconductor nanocrystals disposed over the substrate, and second electrode disposed over the emissive layer comprising semiconductor nanocrystals, wherein, when the device is curved, the emissive layer comprising semiconductor nanocrystals lies substantially in the neutral plane of the device. In another embodiment, a light-emitting device includes an emissive layer comprising semiconductor nanocrystals disposed between two flexible substrates, a first electrode disposed over the emissive layer comprising semiconductor nanocrystals, and a second electrode disposed under the emissive layer comprising semiconductor nanocrystals.

Abstract: A light emitting device with a stair quantum well structure in an active region. The stair quantum well structure may include a primary well and a single step or multiple steps. The light emitting device may be a nonpolar, semipolar or polar (Al,Ga,In)N based light emitting device. The stair quantum structure improves the radiative efficiency of the light emitting device.

Abstract: A semiconductor light-emitting element including a substrate, a laminated semiconductor layer including a light-emitting layer formed over the substrate, one electrode (111) formed over the upper face of the laminated semiconductor layer, and an other electrode formed over the exposed surface of the semiconductor layer, from which the laminated semiconductor layer is partially cut off. The one electrode (111) includes a junction layer (110) and a bonding pad electrode (120) formed to cover the junction layer. The bonding pad electrode has a maximum thickness larger than that of the junction layer, and is composed of one or two or more layers. Slopes (110c), (117c) and (119c), which are made gradually thinner toward the outer circumference, are formed in the outer circumference portions (110d) and (120d) of the junction layer and the bonding pad electrode. Also disclosed is a method for manufacturing the element and a lamp.

Abstract: A nitride-based light-emitting device includes a substrate and a plurality of layers formed over the substrate in the following sequence: a nitride-based buffer layer formed by nitrogen, a first group III element, and optionally, a second group III element, a first nitride-based semiconductor layer, a light-emitting layer, and a second nitride-based semiconductor layer.

Abstract: A nitride semiconductor device comprises: a layer structure including an active region (102) containing AlxGayIn1-x-yN quantum dots layers (102a), and means (104a,104b) for applying an electric field across the active region to modify the spin orientation of excitons in the quantum dots. The exciton spin lifetime at 300K is, for at least a range of values of the electric field applied across the active region, at least 1 ns, more preferably at least 10 ns, and particularly preferably at least 15 ns or 20 ns. These lifetimes may be obtained by configuring the device such that the exciton binding energy is, for at least a range of values of the electric field applied across the active region, 25 meV or greater.

Abstract: A method for manufacturing a light emitting diode (LED) assembly comprises the steps of: covering a light-reflection layer onto a substrate layer, covering a light-emitting layer onto the light-reflection layer, and forming a P type electrode and an N type electrode extended from the light-emitting layer, perforating through the light-reflection layer, and exposed from the substrate layer to form an LED chip structure; packaging the LED chip structure with a light-transmissible packaging material and keeping the P type electrode and the N type electrode exposed from the light-transmissible packaging material to form a molded LED chip cell; and electrically connecting the P type electrode and the N type electrode of the molded LED chip cell to a circuit board, so as to manufacture the LED assembly.

Abstract: LED packaged structures and applications thereof are disclosed, characterized in that: an active layer in the LED or the LED packaged structure is formed on a first semiconductor conductive layer with multi-quantum wells; and a second semiconductor conductive layer is formed on the active layer; wherein a plurality of particles formed by at least one hetero-material are scattered between the first semiconductor conductive layer and the active layer in order to form an uneven multi-quantum well.

Abstract: A light source and method for fabricating the same are disclosed. The light source includes a substrate and a light emitting structure. The substrate has a first surface and a second surface, the second surface including a curved, convex surface with respect to the first surface of the substrate. The light emitting structure includes a first layer of a material of a first conductivity type overlying the first surface, an active layer overlying the first layer, the active layer generating light when holes and electrons recombine therein, and a second layer includes a material of a second conductivity type overlying the active layer and a second surface opposite to the first surface. A mirror layer overlies the light emitting structure.

Abstract: The present disclosure relates to a III-nitride semiconductor light emitting device which improves external quantum efficiency by using a p-type nitride semiconductor layer with a rough surface, the p-type nitride semiconductor layer including: a first nitride semiconductor layer with a first doping concentration, a second nitride semiconductor layer with a second doping concentration lower than the first doping concentration and with the rough surface, and a third nitride semiconductor layer with a higher doping concentration than a second doping concentration.

Abstract: In various embodiments, the present invention relates to a plurality of coated primary particles, each primary particle including a primary matrix material and containing a population of semiconductor nanoparticles, wherein each primary particle is provided with a separate layer of a surface coating material. Various methods of preparing such particles are described. Composite materials and light-emitting devices incorporating such primary particles are also described.

Abstract: In various embodiment, a primary particle includes a primary matrix material containing a population of semiconductor nanoparticles, with each primary particle further comprising an additive to enhance the physical, chemical and/or photo-stability of the semiconductor nanoparticles. A method of preparing such particles is described. Composite materials and light-emitting devices incorporating such primary particles are also described.

Abstract: A dislocation-free high quality template with relaxed lattice constant, fabricated by spatially restricting misfit dislocation(s) around heterointerfaces. This can be used as a template layer for high In composition devices. Specifically, the present invention prepares high quality InGaN templates (In composition is around 5-10%), and can grow much higher In-composition InGaN quantum wells (QWs) (or multi quantum wells (MQWs)) on these templates than would otherwise be possible.

Abstract: A light emitting element according to an exemplary embodiment includes: a support substrate; a second electrode layer formed on the support substrate; a current spreading layer formed on the support substrate; a second conductive semiconductor layer formed on the second electrode layer and the current spreading layer; an active layer formed on the second conductive semiconductor layer; a first conductive semiconductor layer formed on the active layer; and a first electrode layer formed on the first conductive semiconductor layer.

Abstract: A new light emitting device is disclosed, including a polarizing surface layer, a light emitting layer which emits light at a wavelength, and a light transformation layer disposed between the light emitting layer and the reflective layer, wherein the light emitting layer is disposed between the reflective layer and the polarizing surface layer, and an optical thickness between the light emitting layer and the reflective layer is less than a value of five times of a quarter of the wavelength.

Abstract: A III-nitride film, grown on an m-plane substrate, includes multiple quantum wells (MQWs) with a barrier thickness of 27.5 nm or greater and a well thickness of 8 nm or greater. An emission wavelength can be controlled by selecting the barrier thickness of the MQWs. Device fabricated using the III-nitride film include nonpolar III-nitride light emitting diodes (LEDs) with a long wavelength emission.

Abstract: Epitaxial formation structures and associated methods of manufacturing solid state lighting (“SSL”) devices with target thermal expansion characteristics are disclosed herein. In one embodiment, an SSL device includes a composite structure having a composite CTE temperature dependency, a formation structure on the composite structure, and an SSL structure on the formation structure. The SSL structure has an SSL temperature dependency, and a difference between the composite CTE and SSL temperature dependencies is below 3 ppm/° C. over the temperature range.

Abstract: An optoelectronic light emitting semiconductor device is provided comprising an active region, a p-type Group III nitride layer, an n-type Group III nitride layer, a p-side metal contact layer, an n-side metal contact layer, and an undoped tunneling enhancement layer. The p-side metal contact layer is characterized by a work function W satisfying the following relation: W?e?AFF±0.025 eV where e?AFF is the electron affinity of the undoped tunneling enhancement layer. The undoped tunneling enhancement layer and the p-type Group III nitride layer comprise conduction and valence energy bands. The top of the valence band V1 of the undoped tunneling enhancement layer is above the top of the valence band V2 of the p-type Group III nitride layer at the band offset interface to generate a capacity for a relatively high concentration of holes in the undoped tunneling enhancement layer at the band offset interface. Additional embodiments are disclosed and claimed.

Abstract: A nitride semiconductor light emitting diode according to the present invention, includes: a substrate; a buffer layer formed on the substrate; an In-doped GaN layer formed on the buffer layer; a first electrode layer formed on the In-doped GaN layer; an InxGa1?xN layer formed on the first electrode layer; an active layer formed on the InxGa1?xN layer; a first P—GaN layer formed on the active layer; a second electrode layer formed on the first P—GaN layer; a second P—GaN layer partially protruded on the second electrode layer; and a third electrode formed on the second P—GaN layer.

Abstract: An optoelectronic semiconductor chip is specified, which has an active zone (20) containing a multi quantum well structure provided for generating electromagnetic radiation, which comprises a plurality of successive quantum well layers (210, 220, 230). The multi quantum well structure comprises at least one first quantum well layer (210), which is n-conductively doped and which is arranged between two n-conductively doped barrier layers (250) adjoining the first quantum well layer. It comprises a second quantum well layer (220), which is undoped and is arranged between two barrier layers (250, 260) adjoining the second quantum well layer, of which one is n-conductively doped and the other is undoped. In addition, the multi quantum well structure comprises at least one third quantum well layer (230), which is undoped and which is arranged between two undoped barrier layers (260) adjoining the third quantum well layer.

Abstract: Disclosed herein is a nitride-based semiconductor light-emitting device. The nitride-based semiconductor light-emitting device comprises an n-type clad layer made of n-type Alx1Iny1Ga(1-x1-y1)N (where 0?x1?1, 0?y1?1, and 0?x1+y1?1), a multiple quantum well-structured active layer made of undoped InAGa1-AN (where 0<A<1) formed on the n-type clad layer, and a p-type clad layer formed on the active layer wherein the p-type clad layer includes at least a first layer made of p-type Iny2Ga1-y2N (where 0?y2<1) formed on the active layer and a second layer made of p-type Alx3Iny3Ga(1-x3-y3)N (where 0<x3?1, 0?y3?1, and 0<x3+y3?1) formed on the first layer.