Abstract: An LED or microLED light source with multiple light-emitting diode stacks separated by tunnel junction(s). The diode stacks of the light source are independently addressable leading to a light source with high light output range.

Abstract: Provided is a monolithic active matrix pixel with a polychromatic RGB micro-LED and field effect transistors (FET) on the same epitaxial wafer. The field effect transistors are gallium nitride (GaN)-based. The polychromatic RGB micro-LED is formed on a transistor channel layer on the epitaxial wafer. The polychromatic RGB micro-LED has four electrode terminals, one of which is a common anode or a common cathode.

Abstract: Provided is a three p-n junction polychromatic LED compatible with synchronous driving of multiple junctions at low applied voltage. Semiconductor contact layers are isolated from each other by inserting epitaxial current blocking layers between them. Two of the p-n junctions are connected in parallel to the cathode (or anode) using the same n-type layer which allows for a configuration with only five terminals. The reduced number of contact terminals facilitates wafer fab processing and allows for a smaller pixel pitch or larger light-emitting area at a given pitch.

Abstract: Three sets of LED layers each include p-doped and n-doped layers with an active layer therebetween, a tunnel junction layer against the p-doped layer, and an additional n-doped layer against the tunnel junction layer. The first and second LED layer sets are separated by a first semi-insulating semiconductor layer; the second and third LED layer sets are separated by a second semi-insulating semiconductor layer; the second LED layer set is between the first and second semi-insulating semiconductor layers; the third semiconductor layer set is between the second semi-insulating layer and a dielectric layer. Cathode contacts extend through the dielectric layer to the n-doped layers; anode contacts extend through the dielectric layer to the additional n-doped layers. The three LED layer sets can independently emit light at three different corresponding wavelengths, e.g., red, green, and blue light that can encompass an sRGB color gamut or can yield white light.

Abstract: 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.

Abstract: A light-emitting device includes red InGaN-based LED(s), green III-nitride-based LED(s), and blue III-nitride-based LED(s), which respectively emit red emitted light, green emitted light, and blue emitted light. Spectrally selective optical element(s), on which at least the red emitted light is incident, result in red output light having a red output color point, green output light having a green output color point, and blue output light having a blue output color point. The red, green, and blue output color points define a color gamut that encompasses at least an sRGB color gamut, in some examples even when corresponding color points of the red, green, and blue emitted light do not.

Abstract: Described are light emitting diode (LED) devices including a quantum well on a superlattice structure. The LED device has a dominant wavelength greater than 520 nm. The dominant wavelength changes less than 7 nm when the current density increases from 10 A/cm2 to 100 A/cm2 and a junction temperature of the device changes less than 20° C.

Abstract: Described are light emitting diode (LED) devices including a quantum well comprising an indium gallium nitride (InGaN) well and a barrier layer. The indium gallium nitride (InGaN) well has an indium concentration greater than 18% mole fraction. The LED device has a dominant wavelength greater than 605 nm at a current density of greater than or equal to 2 A/cm2.

Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: 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.

Abstract: Provided is a monolithically integrated red green blue (RGB) light emitting diode (LED) array manufactured with a reduced number of mesa etching steps and contact terminals. The LED array may have two or three p-n-junctions grown sequentially on a wafer. One of the p-n junctions has the opposite order of deposition of the n- and p-layers. A light-emitting active region is embedded between the n- and p-layers of each of the p-n junctions. Each active region emits light of different wavelength. The wafer is etched into multi-level mesas, creating two separate voltage terminals and a ground contact to control the bias between particular semiconductor layers. All of the p-n junctions share a common ground contact.

Abstract: Provided is a monolithically integrated red green blue (RGB) light emitting diode (LED) array manufactured with a reduced number of mesa etching steps and contact terminals. The LED array may have two or three p-n-junctions grown sequentially on a wafer. One of the p-n junctions has the opposite order of deposition of the n- and p-layers. A light-emitting active region is embedded between the n- and p-layers of each of the p-n junctions. Each active region emits light of different wavelength. The wafer is etched into multi-level mesas, creating two separate voltage terminals and a ground contact to control the bias between particular semiconductor layers. All of the p-n junctions share a common ground contact.

Abstract: Provided is an LED comprised of a first and a second p-n junction deposited sequentially on the same wafer. The first and second junctions have opposite orders of deposition of the n- and p-layers. One light-emitting active region is embedded between the n- and p-layers of the first junction and another light-emitting active region is embedded between the n- and p-layers of the second junction. Contacts are processed such that forward current can be passed in parallel through both of the junctions using a single voltage source. For a given forward current, the LED operates at lower voltage with higher optical flux and efficiency.

Abstract: Provided is an LED comprised of a first and a second p-n junction deposited sequentially on the same wafer. The first and second junctions have opposite orders of deposition of the n- and p-layers. One light-emitting active region is embedded between the n- and p-layers of the first junction and another light-emitting active region is embedded between the n- and p-layers of the second junction. Contacts are processed such that forward current can be passed in parallel through both of the junctions using a single voltage source. For a given forward current, the LED operates at lower voltage with higher optical flux and efficiency.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.