Lumileds LLC

Antonio Lopez-Julia

Venkata Ananth Tamma

Aimi Abass

Jens Meyer

Hans-Helmut Bechtel

Joerg Feldmann

Ronja Missong

Marcel Van Gerwen

Philipp-Immanuel Schneider

Srinivasa Banna

Thomas Diederich

Jaime Gomez Rivas

Niels Jeroen Van Der Veen

Aleksandr Vaskin

Albert Femius Koenderink

Mohamed S Abdelkhalik

Debapriya Pal

Rémi Guillebot

Joseph Flemish

Jaime Gomez-Rivas

This specification discloses LEDs and LED arrays configured such that an electric field may be applied during operation of the device to drive charge carriers (electrons or holes) away from perimeter semiconductor surfaces of the LEDs, thereby reducing non-radiative recombination near those perimeter surfaces. These LEDs and LED arrays comprise (e.g., metal) field plates, arranged around the perimeter surfaces of the LEDs, by which the electric field may be applied. In some variations, the bias voltage applied to the field plates to produce the electric fields may be separately controlled for some, or each, LED in an array. In other variations the bias applied to the field plates is the same for each LED in an array.

Light emitting diodes comprising field plates

A light-emitting device includes a semiconductor diode structure with one or more light-emitting active layers, an anti-reflection coating on its front surface, and a redirection layer on its back surface. Active-layer output light propagates within the diode structure. The anti-reflection coating on the front surface increases transmission of active-layer output light incident below the critical angle Θc. Active-layer output light incident on the redirection layer at an incidence angle greater than Θc is redirected to propagate toward the front surface at an incidence angle that is less than Θc. Device output light is transmitted by the front surface to propagate in an ambient medium, and includes first and second portions of the active-layer output light incident on the front surface at an incidence angle less than Θc, the first portion without redirection by the redirection layer and the second portion with redirection by the redirection layer.

Light-emitting device with internal non-specular light redirection and anti-reflective exit surface

A light-emitting device includes: a semiconductor diode structure, a reflector, a wavelength-converting layer, and an intermediate spacer between the diode structure and the wavelength-converting layer. The diode structure emits diode output light at a vacuum wavelength λto propagate within the diode structure. The reflector is on the back diode structure and internally reflects diode internally incident output light. The wavelength-converting layer is positioned with its back surface facing and spaced-apart from a front surface of the diode structure, and absorbs diode output light at λand emits down-converted light at a vacuum wavelength λ>λ, which exits the wavelength-converting layer through its front surface. The intermediate spacer includes one or more transparent dielectric layers and has an effective refractive index less than that of the wavelength-converting layer, so that the wavelength-converting layer acts as an optical waveguide supporting one or more laterally propagating optical modes at λand λ.

Phosphor-converted light-emitting diode with dielectric spacer

Optical filters are used to compensate for changes in LED and pcLED performance resulting from technological advances in device design or manufacturing, with for example the filtered optical output from later generation devices matching or substantially matching the optical performance of earlier generation legacy devices. This can allow the advanced generation devices to be substituted in applications previously supported by the legacy devices, even if the optical performance of the unfiltered advanced generation devices does not satisfy the optical performance specifications required by the application. Somewhat paradoxically, the advantages of using the filters in combination with the advanced generation devices may arise from the filters making the optical performance of the devices worse according to one or more figures of merit.

Optical filters compensating for changes in performance of next generation LEDs compared to legacy devices

A nano-structure layer is disclosed. The nano-structure layer includes an array of nano-structure material configured to receive a first light beam at a first angle of incidence and to emit the first light beam at a second angle greater than the first angle, the nano-structure material each having a largest dimension of less than 1000 nm.

Color uniformity in converted light emitting diode using nano-structures

A light-emitting array includes a semiconductor LED structure, multiple transparent dielectric bodies, a set of multiple, independent first electrical contacts, and a set of second electrical contacts. The LED structure extends contiguously over the array. The second electrical contacts are in electrical contact with the second semiconductor layer. Each dielectric body protrudes away from the first semiconductor layer and has on its surface an electrically conductive layer in electrical contact with the first semiconductor layer, forming a portion of a corresponding one of the first electrical contacts. Each dielectric body and corresponding first electrical contact define a corresponding discrete, circumscribed pixel region within the contiguous area of the array, each pixel region separate from the others. Some light emitted in the pixel region propagates into the dielectric body, undergoes internal reflection(s) within the dielectric body, and propagates out of the array through the dielectric body and diode structure.

Light-emitting array with dielectric light collection structures

An optical coupling structures are disposed on light output surfaces of semiconductor LEDs of a miniLED or microLED array to facilitate coupling of light emitted by the semiconductor LEDs through the light output surfaces. The optical coupling structures comprise light scattering particles and/or air voids embedded in or coated with a thin layer of a material that has an index of refraction close to or matching the index of refraction of the material forming the light output surface of the semiconductor LEDs.

Optical coupling layer to improve output flux in LEDs

A light-emitting device includes a semiconductor diode structure with one or more light-emitting active layers, an anti-reflection coating on its front surface, and a redirection layer on its back surface. Active-layer output light propagates within the diode structure. The anti-reflection coating on the front surface increases transmission of active-layer output light incident below the critical angle &#x398;. Active-layer output light incident on the redirection layer at an incidence angle greater than &#x398;is redirected to propagate toward the front surface at an incidence angle that is less than &#x398;. Device output light is transmitted by the front surface to propagate in an ambient medium, and includes first and second portions of the active-layer output light incident on the front surface at an incidence angle less than &#x398;, the first portion without redirection by the redirection layer and the second portion with redirection by the redirection layer.

A device comprising a light emitting diode (LED) substrate, and a meta-molecule wavelength converting layer positioned within an emitted light path from the LED substrate, the a meta-molecule wavelength converting layer including a plurality of nanoparticles, the plurality of nanoparticles configured to increase a light path length in the wavelength converting layer.

LED with structured layers and nanophosphors

A light-emitting device assembly includes a concave optical collector, a light-emitting device, and a light-escape surface. The collector redirects incident light by reflection, scattering, or reradiation. The light-emitting device emits device output light to propagate within the optical collector. The light-escape surface extends across an open end of the collector and exhibits (i) incidence-angle-dependent transmission of light that decreases with increasing incidence angle, or (ii) transmissive redirection of light to propagate at an angle less than a corresponding refracted angle, that are imparted by an array of nano-antennae, a partial photonic bandgap structure, a photonic crystal, an array of meta-atoms or meta-molecules, or a multi-layer dielectric thin film. Assembly output light transmitted by the light-escape surface includes first and second portions of the device output light that propagate within the collector without and with redirection, respectively, within the collector by the light-escape surface.

Light-emitting device assembly with light redirection or incidence-angle-dependent transmission through an escape surface

An optical coupling structure is disposed on a light output surface of a semiconductor LED to facilitate coupling of light emitted by the semiconductor LED through the light output surface. The optical coupling structures comprise light scattering particles and/or air voids embedded in or coated with a thin layer of a material that has an index of refraction close to or matching the index of refraction of the material forming the light output surface of the semiconductor LED.

A nano-structure layer is disclosed. The nano-structure layer includes a plurality of nano-photonic structures that are configured in a first configuration such that light incident upon the nano-structured layer below a cutoff angle passes through the nano-structured layer and light incident upon the nano-structured layer above the cutoff angle is reflected back in direction of the incidence.

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Aachen, Germany

Antonio Lopez-Julia