Abstract: The invention provides a method and device for light generation wherein an embodiment of the device comprises a lower electrode, a conducting substrate formed on the lower electrode, and a triangle mesa structure having an optical cavity formed on the substrate. The triangle mesa structure (which can also be truncated) further comprises an active layer, a lower conducting mirror and an upper conducting mirror for vertical confinement of light in the optical cavity, a contact layer formed on the upper mirror, a metallic contact formed on the contact layer. An electrical current is applied to the device according to the invention through the metallic contact linked to the contact layer, and subsequently to the lower electrode through the lower mirror and the conducting substrate. The applied current results in light generation in the active layer with vertical light output through the metallic contact. A corresponding light generation method is also disclosed herein.

Abstract: An LED based on a two well system with charge asymmetric resonance tunnelling comprises first and second coupled wells, one being a wide well and the other an active quantum well. The wells are coupled via a resonance tunnelling barrier which is transparent for electrons and blocking for holes.

Abstract: The invention provides a light emitting diode (LED) or other light emitting means such as a laser diode (LD) comprising a light emitting component and scattering optical media such as dielectric phosphor powder (DPP) which absorb a part of light emitted by the light emitting component and emits light of a wavelength that is different from that of the absorbed light. In a preferred embodiment according to the invention, the LED includes a crystalline semiconductor chip serving as the light emitting component. The scattering optical media such as dielectric phosphor powder (DPP) is made of a mixture of phosphor particles and microscopic, nearly spherical dielectric particles with a band gap larger than 3 eV (which do not absorb blue light in the spectrum). The scattering optical media such as DPP can also include phosphor particles, and bubbles (or voids) instead of the dielectric particles. The bubbles of the DPP have a band gap larger than 3 eV which do not absorb blue light in the spectrum.

Abstract: The invention provides a method and device for light generation wherein the device comprises a lower electrode, a substrate formed on the lower electrode, a triangle mesa structure formed on the substrate for lateral confinement of light, a triangle optical cavity formed in the mesa structure, an upper electrode formed on the mesa structure, and a plurality of contact spots formed on the upper electrode corresponding to the maxima of optical field intensity for at least one optical mode on a lateral plane in the triangle optical cavity. Another embodiment of the device according to the invention further comprises a plurality of triangle mesa structures, along with a light output structure for directing and controlling light output from the device, which are formed on the substrate in various topologies such as a matrix or an array.

Abstract: The fabrication of unipolar light emitting devices (ULEDs) based on III-nitride semiconductors is disclosed using an effective “p-n junction” between two n-type III-nitride semiconductor superlattices. Such a device works like a usual light emitting diode at forward bias but the radiation arises not due to recombination of electrons and holes but due to electron transitions from a shallow sub-band superlattice into a deep sub-band superlattice.

Abstract: The present invention relates to light omitting diodes having an AlGaInP active layer disposed between two cladding layers of AlGaInP, with a strain layer grown on the second cladding layer and comprising a superlattice structure in the form of a plurality of thin alternated AlGaInP layers with preselected composition. In one embodiment, the composition of the alternated AlGaInP layers is an ohmic n-electrode on a rear surface of a GaAs substrate: a distributed AlGaAs Bragg reflecting layer in the form of a multi-layer lamination; a first, lower AlGaInP cladding layer grown on the reflecting layer; an AlGaInP active layer grown on the lower cladding layer; a second, upper AlGaInP cladding layer grown on the active layer; a strain layer grown on the second cladding layer, the strain layer comprising a superlattice structure in the form of a plurality of thin alternated AlGaInP layers with the composition: (AlxGa1-x)1-yInyP/(AlnGa1-n)1-hInhP, where 0.5≦x≦1; 0.4≦y≦0.6/0≦a≦0.4; 0≦b≦0.4.

Abstract: The invention provides a light emitting diode (LED) or other light emitting means such as a laser diode (LD) comprising a light emitting component and scattering optical media such as dielectric phosphor powder (DPP) which absorb a part of light emitted by the light emitting component and emits light of a wavelength that is different from that of the absorbed light. In a preferred embodiment according to the invention, the LED includes a crystalline semiconductor chip serving as the light emitting component. The scattering optical media such as dielectric phosphor powder (DPP) is made of a mixture of phosphor particles and microscopic, nearly spherical dielectric particles with a band gap larger than 3 eV (which do not absorb blue light in the spectrum). The scattering optical media such as DPP can also include phosphor particles, and bubbles (or voids) instead of the dielectric particles. The bubbles of the DPP have a band gap larger than 3 eV which do not absorb blue light in the spectrum.

Abstract: A semiconductor device has a window layer (8), a current spreading layer (7) below the window layer and a cladding layer (6) below the current spreading layer. The band gap energy of the spreading layer is higher than that of the window layer and lower than that of the cladding layer and the carrier concentration of the spreading layer is lower than that of the window layer and higher than that of the cladding layer.

Abstract: A method for growth of strain free epitaxial layers of semiconductors on highly lattice mismatched substrates is suggested using a buffer layer with a solid-liquid phase transition to accommodate high mismatch between substrate and semiconductor.

Abstract: A semiconductor light emitting device includes two AlGaAs and AlGaInP Bragg reflector layers below an active layer.