Sharp Kabushiki Kaisha Corporation

Jonathan Heffernan

Stewart Edward Hooper

Valerie Bousquet

Jennifer Mary Barnes

Katherine L Johnson

Peter Neil Taylor

Stephen Day

Thomas Heinz-Helmut Altebaeumer

Matthias Kauer

Rakesh Roshan

Tim Michael Smeeton

Alistair Henderson Kean

Brendan Poole

Christian Lang

Koji Takahashi

David James Montgomery

Hidenori Kawanishi

Benjamin James Hadwen

Valerie Berryman-Bousquet

Tong Zhang

Geoffrey Duggan

Wei-Sin Tan

James Andrew Robert Dimmock

Michael Alan Schreuder

Ying Jun James Huang

Alastair James Daniel Grundy

The present application provides nitride semiconductor nanoparticles, for example nanocrystals, made from a new composition of matter in the form of a novel compound semiconductor family of the type group II-III-N, for example ZnGaN, ZnInN, ZnInGaN, ZnAlN, ZnAlGaN, ZnAlInN and ZnAlGaInN. This type of compound semiconductor nanocrystal is not previously known in the prior art. The invention also discloses II-N semiconductor nanocrystals, for example ZnN nanocrystals, which are a subgroup of the group II-III-N semiconductor nanocrystals. The composition and size of the new and novel II-III-N compound semiconductor nanocrystals can be controlled in order to tailor their band-gap and light emission properties. Efficient light emission in the ultraviolet-visible-infrared wavelength range is demonstrated. The products of this invention are useful as constituents of optoelectronic devices such as solar cells, light emitting diodes, laser diodes and as a light emitting phosphor material for LEDs and emissive EL displays.

II-III-N semiconductor nanoparticles and method of making same

A method of producing nitride nanoparticles comprises reacting at least one organometallic compound, for example an alkyl metal, with at least one source of nitrogen. The reaction may involve one or more liquid phase organometallic compounds, or may involve one or more liquid phase organometallic compounds dissolved in a solvent or solvent mixture. The reaction constituents may be heated to a desired reaction temperature (for example in the range 40&#xb0; C. to 300&#xb0; C.).

Method of synthesising nitride nanocrystals

An illumination system comprises at least two light sources () having different emission spectra to one another; a detection circuit () for sensing a light intensity using at least one of the light sources as a photosensor; and driving means () for driving the light source in dependence on the sensed spectral distribution of light. The emission spectrum of a light source with the smallest bandgap overlaps the emission spectrum of a light source with the second-smallest bandgap. The illumination system is possible to measure the intensity of light emitted by the light source with the smallest bandgap by putting the light source with the second-smallest bandgap in detection mode. The illumination system may also sense the spectral distribution of ambient light, to allow the output from the illumination system to be adjusted in dependence on the ambient light.

Solid state illumination system

A resonant tunneling device includes a first semiconductor material with an energy difference between valence and conduction bands of E, and a second semiconductor material with an energy difference between valence and conduction bands of E, wherein Eand Eare different from one another. The device further includes an energy selectively transmissive interface connecting the first and second semiconductor materials.

Energy conversion device with selective contacts

A method of manufacturing a nitride nanoparticle comprises manufacturing the nitride nanostructure from constituents including: a material containing metal, silicon or boron, a material containing nitrogen, and a capping agent having an electron-accepting group for increasing the quantum yield of the nitride nanostructure. Nitride nanoparticles, for example nitride nanocrystals, having a photoluminescence quantum yield of at least 1%, and up to 20% or greater, may be obtained.

Fabrication of nitride nanoparticles

A method of growing a thin film comprises growing a thin film by conformally forming at least one layer over a substrate having structures extending from a surface of the substrate, whereby the or each layer is formed over the surface of the substrate and over the structures extending from the surface. The thickness of the conformal layer, or the sum of the thicknesses of the conformal layers, is at least half the average spacing of the structures, and; at least one of the height of the structures, the average spacing of the structures and the size of the smallest dimension of the structures is set so as to provide an enhanced growth rate for the or each conformal layer (compared to the growth rate over a planar substrate).

Method of growing a thin film, a method of forming a structure and a device

The present application provides a light-emissive nitride nanoparticle, for example a nanocrystal, having a photoluminescence quantum yield of at least 1%. This quantum yield is significantly greater than for prior nitride nanoparticles, which have been only weakly emissive and have had poor control over the size of the nanoparticles produced. The nanoparticle includes at least one capping agent provided on a surface of the nitride crystal and containing an electron-accepting group for passivating nitrogen atoms at the surface of the crystal. The invention also provides non-emissive nitride nanoparticles.

Nanoparticles

A method includes forming elongate structures on a first substrate, such that the material composition of each elongate structure varies along its length so as to define first and second physically different sections in the elongate structures. First and second physically different devices are then defined in the elongate structures. Alternatively, the first and second physically different sections may be defined in the elongate structures after they have been fabricated. The elongate structures may be encapsulated and transferred to a second substrate. The invention provides an improved method for the formation of a circuit structure that requires first and second physically different devices to be provided on a common substrate. In particular, only one transfer step is necessary.

Multifunctional tape

A light emitting diode device which includes at least one light emitting diode, a heat-sink chassis having a surface upon which the at least one light emitting diode is mounted, and a waveguide having one end coupled to the at least one light emitting diode for receiving light therefrom. The waveguide has another end which includes a light extraction and redistribution region, and the waveguide is configured to guide light received from the at least one light emitting diode away from the heat-sink chassis and towards the light extraction and redistribution region. The light extraction and redistribution region is configured to extract and redistribute the light from the waveguide.

Light emitting diode device

A method of fabricating a device structure, comprises: forming an insulating layer () over a first set of devices disposed over a substrate (); forming one or more vias in the insulating layer; disposing a second set of devices () over the insulating layer, wherein devices of the second set comprise respective electrical contacts () and are disposed over the insulating layer () such that a side on which a contact () can be accessed faces the substrate (); and forming one or more electrical contacts between the first set of devices and the second set of devices () through the via(s). The second set of devices and at least one via are positioned such that one or more of the vias lies at least partially within the footprint of two devices, each belonging to a different device layer.

Device interconnects

A method of manufacturing a nitride semiconductor structure includes disposing a semiconductor substrate in a molecular beam epitaxy reactor; growing a wetting layer comprising AlInGa()As(0&#x2266;x+y&#x2266;1) or AlInGa()P(0&#x2266;x+y&#x2266;1) on the substrate; in-situ annealing the wetting layer; growing a first AlGaInN layer on the wetting layer using plasma activated nitrogen as the source of nitrogen with an additional flux of phosphorous or arsenic; and growing a second AlGaInN layer on the first AlGaInN layer using ammonia as a source of nitrogen.

Semiconductor structure and method of manufacture of same

A method includes forming elongate structures () on a first substrate (), such that the material composition of each elongate structure () varies along its length so as to define first and second physically different sections in the elongate structures. First and second physically different devices () are then defined in the elongate structures. Alternatively, the first and second physically different sections may be defined in the elongate structures after they have been fabricated. The elongate structures may be encapsulated and transferred to a second substrate (). The invention provides an improved method for the formation of a circuit structure that requires first and second physically different devices () to be provided on a common substrate. In particular, only one transfer step is necessary.

A method of fabricating a continuous wave semiconductor laser diode in the (Al,Ga,In)N materials system comprises: growing, in sequence, a first cladding region (), a first optical guiding region (), an active region (), a second optical guiding region () and a second cladding region (). Each of the first cladding region (), the first optical guiding region (), the active region (), the second optical guiding region () and the second cladding region () is deposited by molecular beam epitaxy.

MBE growth of a semiconductor laser diode

A method of growing a p-type nitride semiconductor material by molecular beam epitaxy (MBE) uses bis(cyclopentadienyl)magnesium (Cp2Mg) as the source of magnesium dopant atoms. Ammonia gas is used as the nitrogen precursor for the MBE growth process. To grow p-type GaN, for example, by the method of the invention, gallium, ammonia and Cp2Mg are supplied to an MBE growth chamber; to grow p-type AlGaN, aluminum is additionally supplied to the growth chamber. The growth process of the invention produces a p-type carrier concentration, as measured by room temperature Hall effect measurements, of up to 2 1017 cm&#x2212;3, without the need for any post-growth step of activating the dopant atoms.

Growing community of inventors

Oxford, United Kingdom

Jonathan Heffernan