Lumileds LLC

Other

Koninklijke Philips Corporation N.v.

Isaac Wildeson

Parijat Deb

Robert David Armitage

Erik Charles Nelson

Kenneth John Vampola

Toni Lopez

Patrick Nolan Grillot

Tigran Nshanian

Junko Kobayashi

Hossein Lotfi

Oleg Borisovich Shchekin

Tsutomu Ishikawa

Hee-Jin Kim

Ronald Johannes Bonne

Aimi Abass

Parijan Pramil Deb

A light emitting diode (LED) device comprises a plurality of pixels on a backplane, each pixel comprising: semiconductor layers, which include an N-type layer, an active region, and a P-type layer; a cathode electrically contacting the N-type layer; an anode comprising anode segments electrically contacting respective portions of the P-type layer; one or more dielectric materials insulating: the active region and the P-type layer from the cathode, the anode segments from each other, and the anode segments from the cathode; and a plurality of interconnects, each respective interconnect affixing a respective anode segment to the backplane. Methods of making and use the devices are also provided.

Light emitting diodes with segmented anodes by pixel

Described are light emitting diode (LED) devices having patterned substrates and methods for effectively growing epitaxial III-nitride layers on them. A nucleation layer, comprising a III-nitride material, is grown on a substrate before any patterning takes place. The nucleation layer results in growth of smooth coalesced III-nitride layers over the patterns.

Light emitting diode (LED) devices with nucleation layer

An LED structure includes an epi layer grown on a substrate and a plurality of dielectric nanoantennas positioned within the epi layer. The dielectric antennas can be periodically arranged to reduce reabsorption of light and redirect oblique incident light to improve overall light coupling efficiency. Each of the dielectric nanoantennas can have a top, a bottom, a height less than 1000 nm and greater than 200 nm and a diameter less than 2000 nm and greater than 300 nm.

Nanocone arrays for enhancing light outcoupling and package efficiency

LED arrays comprise patterned reflective grids that enhance the contrast ratio between adjacent pixels or adjacent groups of pixels in the array. The pattern on the reflective grid may also improve adhesion between the reflective grid and one or more layers of material disposed on and attached to the reflective grid. The reflective grid may be formed, for example, as a reflective metal grid, a grid of dielectric reflectors, or a grid of distributed Bragg reflectors (DBRs). If formed as a metal grid, the reflective grid may provide electrical contact to one side of the LED diode junctions. This specification also discloses fabrication processes for such LED arrays.

Patterned reflective grids for LED arrays and displays

An LED array comprises a first mesa comprising a top surface, at least a first LED including a first p-type layer, a first n-type layer and a first color active region and a tunnel junction on the first LED, a second n-type layer on the tunnel junction, the second n-type layer comprising at least one n-type III-nitride layer with >10% Al mole fraction and at least one n-type III-nitride layer with <10% Al mole fraction. The LED array further comprises an adjacent mesa comprising a top surface, the first LED, a second LED including the second n-type layer, a second p-type layer and a second color active region. A first trench separates the first mesa and the adjacent mesa, cathode metallization in the first trench and in electrical contact with the first and the second color active regions of the adjacent mesa, and anode metallization contacts on the n-type layer of the first mesa and on the anode layer of the adjacent mesa. The devices and methods for their manufacture include a thin film transistor (TFT).

III-nitride multi-wavelength LED arrays with etch stop layer

An automotive headlight is disclosed including: an optical unit including a plurality of optical elements, each optical element having a different central direction; a segmented light-emitting diode (LED) chip including a plurality of LEDs that are separated by trenches formed on the segmented LED chip and arranged in a plurality of sections, each section being aligned with a different respective optical element, and each section including at least one first LED and at least one second LED; and a controller configured to: apply a forward bias to each of the first LEDs, apply a reverse bias to each of the second LEDs, and change a brightness of the first LEDs in any section based on a signal generated by the second LED in that section.

Optoelectronic device and adaptive illumination system using the same

An LED array comprises a first mesa comprising a top surface, at least a first LED including a first p-type layer, a first n-type layer and a first color active region and a tunnel junction on the first LED, a second n-type layer on the tunnel junction. The LED array further comprises an adjacent mesa comprising a top surface, the first LED, a second LED including the second n-type layer, a second p-type layer and a second color active region. A first trench separates the first mesa and the adjacent mesa, cathode metallization in the first trench and in electrical contact with the first and the second color active regions of the adjacent mesa, and anode metallization contacts on the n-type layer of the first mesa and on the anode layer of the adjacent mesa. The devices and methods for their manufacture include a thin film transistor (TFT).

III-nitride multi-wavelength LED arrays

Described are arrays of light emitting diode (LED) devices and methods for their manufacture. An LED array comprises a first mesa comprising a top surface, at least a first LED including a first p-type layer, a first n-type layer and a first color active region and a tunnel junction on the first LED, the top surface comprising a second n-type layer on the tunnel junction. The LED array further comprises an adjacent mesa comprising a top surface, the first LED, a second LED including the second n-type layer, a second p-type layer and a second color active region. There is a first trench separating the first mesa and the adjacent mesa, n-type metallization in the first trench and in electrical contact with the first color active region and the second color active region of the adjacent mesa, and p-type metallization contacts on the n-type layer of the first mesa and on the p-type layer of the adjacent mesa.

Described are light emitting diode (LED) devices including a combination of electroluminescent and photo-luminescent active regions in the same wafer to provide LEDs with emission spectra that are adjustable after epitaxial growth. The LED device includes a multilayer anode contact comprising a reflecting metal and at least one transparent conducting oxide layer in between the metal and the p-type layer surface. The thickness of the transparent conducting oxide layer may vary for LEDs fabricated with different emission spectra.

Light emitting diode device

An inventive light-emitting apparatus comprises an array of multiple light-emitting pixels, and one or more transmissive optical elements positioned at a light-emitting surface of the light-emitting pixel array. One or more of the light-emitting pixels is defective. Each optical element is positioned at a location of a corresponding defective light-emitting pixel, and extends over that defective pixel and laterally at least partly over one or more adjacent pixels. Each optical element transmits laterally at least a portion of light emitted by the adjacent pixels to propagate away from the array from the location of the defective pixel, reducing the appearance of the defective pixel.

Reduction of defective pixel appearance in light-emitting arrays

Described at light emitting diode (LED) devices emitting different colors on the same wafer, which facilitates their integration with close packing density (not requiring transfer of devices from two different wafers to a third substrate module). The LED devices and driving methods allow light of different colors and similar luminance levels to be emitted for given input current.

Light emitting diode device with tunable emission

Described are light emitting diode (LED) devices including a combination of electroluminescent quantum wells and photo-luminescent active regions in the same wafer. A first group of QWs with shortest emission wavelength is placed between the p- and n-layers of a p-n junction. Other groups of QWs with longer wavelengths are placed outside the p-n junction in a part of the LED structure where electrical injection of minority carriers does not occur. Electroluminescence emitted by the first group of QWs is absorbed by other group(s) and re-emitted as longer wavelength light. The color of an individual die made on the wafer can be controlled by either etching away unwanted groups of longer-wavelength QWs at the position of that die, or keeping them intact. Wavelength-selective mirrors that increase down conversion efficiency may be selectively applied to die where longer wavelength emission is desired. The use of tunnel junction contacts facilitates integration of wavelength selective mirrors to external surfaces of the die and avoids problems of conductivity type conversion on etched p-GaN layers.

An LED array comprises a first mesa comprising a top surface, at least a first LED including a first p-type layer, a first n-type layer and a first color active region and a tunnel junction on the first LED, a second n-type layer on the tunnel junction, the second n-type layer comprising at least one n-type III-nitride layer with &#x3e;10% Al mole fraction and at least one n-type III-nitride layer with &#x3c;10% Al mole fraction. The LED array further comprises an adjacent mesa comprising a top surface, the first LED, a second LED including the second n-type layer, a second p-type layer and a second color active region. A first trench separates the first mesa and the adjacent mesa, cathode metallization in the first trench and in electrical contact with the first and the second color active regions of the adjacent mesa, and anode metallization contacts on the n-type layer of the first mesa and on the anode layer of the adjacent mesa. The devices and methods for their manufacture include a thin film transistor (TFT).

Growing community of inventors

San Jose, CA, United States of America

Isaac Wildeson