Abstract: In accordance with the invention, a light emitting device includes a substrate, a layer of first conductivity type overlying the substrate, a light emitting layer overlying the layer of first conductivity type, and a layer of second conductivity type overlying the light emitting layer. A plurality of vias are formed in the layer of second conductivity type, down to the layer of first conductivity type. The vias may be formed by, for example, etching, ion implantation, or selective growth of the layer of second conductivity type. A set of first contacts electrically contacts the layer of first conductivity type through the vias. A second contact electrically contacts the layer of second conductivity type. In some embodiments, the area of the second contact is at least 75% of the area of the device. In some embodiments, the vias are between 2 and 100 microns wide and spaced between 5 and 1000 microns apart.

Abstract: A lamp has LED sources that are placed about a lamp axis in an axial arrangement. The lamp includes a post with post facets where the LED sources are mounted. The lamp includes a segmented reflector for guiding light from the LED sources. The segmented reflector includes reflective segments each of which is illuminated primarily by light from one of the post facets (e.g., one of the LED sources on the post facet). The LED sources may be made up of one or more LED dies. The LED dies may include optic-on-chip lenses to direct the light from each post facet to a corresponding reflective segment. The LED dies may be of different sizes and colors chosen to generate a particular far-field pattern.

Abstract: P-type layers of a GaN based light-emitting device are optimized for formation of Ohmic contact with metal. In a first embodiment, a p-type GaN transition layer with a resistivity greater than or equal to about 7 &OHgr;cm is formed between a p-type conductivity layer and a metal contact. In a second embodiment, the p-type transition layer is any III-V semiconductor. In a third embodiment, the p-type transition layer is a superlattice. In a fourth embodiment, a single p-type layer of varying composition and varying concentration of dopant is formed.

Abstract: A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n>2.0 and light absorption coefficient &agr;, at the emission wavelength of the active region, of &agr;>3 cm−1. In a preferred embodiment, the substrate material has a refractive index n>2.3, and the light absorption coefficient, &agr;, of the substrate material is &agr;<1 cm−1.

Abstract: A dielectric layer is formed on the mesa wall of a flip-chip LED. The dielectric layer is selected to maximize reflection of light incident at angles ranging from 10 degrees towards the substrate to 30 degrees away from the substrate. In some embodiments, the LED is a III-nitride device with a p-contact containing silver, the dielectric layer adjacent to the mesa wall is a material with a low refractive index compared to GaN, such as Al2O3.

Abstract: A method of forming a photoresist mask on a light emitting device is disclosed. A portion of the light emitting device is coated with photoresist. A portion of the photoresist is exposed by light impinging on the interface of the light emitting device and the photoresist from inside the light emitting device. The photoresist is developed, removing either the exposed photoresist or the unexposed photoresist. In one embodiment, the photoresist mask may be used to form a phosphor coating. After the photoresist is developed to remove the exposed photoresist, a phosphor layer is deposited overlying the light emitting device. The unexposed portion of photoresist is stripped. In some embodiments, the light exposing the photoresist is produced by electrically biasing the light emitting device, or by shining light into the light emitting device through an aperture or by a focussed laser.

Abstract: An inverted III-nitride light-emitting device (LED) with highly reflective ohmic contacts includes n- and p-electrode metallizations that are opaque, highly reflective, and provide excellent current spreading. The n- and p-electrodes each absorb less than 25% of incident light per pass at the peak emission wavelength of the LED active region.

Abstract: The present invention relates to reducing the spatial variation in light output from flipchip LEDs and increasing the consistency in light output from LED to LED in a practical manufacturing process. The present invention introduce appropriate texture into the surface of reflective layer to reduce spatial variation in far-field intensity. At least two reflective planes are provided in the reflective contact parallel to the light emitting region such that at least two interference patterns occur in the light exiting from the LED. The reflective planes are separated by an odd integral multiple of (&lgr;n/4) where &lgr;n is the wavelength of the light in the layer between the active region and the reflective contact, resulting in compensating interference maxima and minima, a more uniform distribution of light, and increased consistency in light output from LED to LED.

Abstract: The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Abstract: The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Abstract: The present invention relates to reducing the spatial variation in light output from flipchip LEDs and increasing the consistency in light output from LED to LED in a practical manufacturing process. The present invention introduce appropriate texture into the surface of reflective layer to reduce spatial variation in far-field intensity. At least two reflective planes are provided in the reflective contact parallel to the light emitting region such that at least two interference patterns occur in the light exiting from the LED. The reflective planes are separated by an odd integral multiple of (&lgr;n/4) where &lgr;n, is the wavelength of the light in the layer between the active region and the reflective contact, resulting in compensating interference maxima and minima, a more uniform distribution of light, and increased consistency in light output from LED to LED.

Abstract: The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Abstract: The present invention is an inverted III-nitride light-emitting device (LED)) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Abstract: A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n>2.0 and light absorption coefficient &agr;, at the emission wavelength of the active region, of &agr;>3 cm−1. In a preferred embodiment, the substrate material has a refractive index n>2.3, and the light absorption coefficient, &agr;, of the substrate material is &agr;<1 cm−1.

Abstract: A light-emitting semiconductor device includes a stack of layers including an active region. The active region includes a semiconductor selected from the group consisting of III-Phosphides, III-Arsenides, and alloys thereof. A superstrate substantially transparent to light emitted by the active region is disposed on a first side of the stack. First and second electrical contacts electrically coupled to apply a voltage across the active region are disposed on a second side of the stack opposite to the first side. In some embodiments, a larger fraction of light emitted by the active region exits the stack through the first side than through the second side. Consequently, the light-emitting semiconductor device may be advantageously mounted as a flip chip to a submount, for example.

Abstract: The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Abstract: P-type layers of a GaN based light-emitting device are optimized for formation of Ohmic contact with metal. In a first embodiment, a p-type GaN transition layer with a resistivity greater than or equal to about 7 &OHgr;cm is formed between a p-type conductivity layer and a metal contact. In a second embodiment, the p-type transition layer is any III-V semiconductor. In a third embodiment, the p-type transition layer is a superlattice. In a fourth embodiment, a single p-type layer of varying composition and varying concentration of dopant is formed.

Abstract: A method for improving the operating stability of compound semiconductor minority carrier devices and the devices created using this method are described. The method describes intentional introduction of impurities into the layers adjacent to the active region, which impurities act as a barrier to the degradation process, particularly undesired defect formation and propagation. A preferred embodiment of the present invention uses O doping of III-V optoelectronic devices during an epitaxial growth process to improve the operating reliability of the devices.

Abstract: A light emitting device includes several LEDs, mounted on a shared submount, and coupled to circuitry formed on the submount. The LEDs can be of the III-Nitride type. The architecture of the LEDs can be either inverted, or non-inverted. Inverted LEDs offer improved light generation. The LEDs may emit light of the same wavelength or different wavelengths. The circuitry can couple the LEDs in a combination of series and parallel, and can be switchable between various configurations. Other circuitry can include photosensitive devices for feedback and control of the intensity of the emitted light, or an oscillator, strobing the LEDs.

Abstract: A light emitting device includes a heterojunction having a p-type layer and an n-type layer. The n-electrode is electrically connected to the n-type layer while the p-electrode is electrically connected to the p-type layer. The p and n-electrodes are positioned to form a region having uniform light intensity.