Sharp Kabushiki Kaisha Corporation

Lightricity Ltd

Matthias Kauer

Jonathan Heffernan

James Andrew Robert Dimmock

Stewart Edward Hooper

Valerie Bousquet

Katherine L Johnson

Valerie Berryman-Bousquet

Diego Gallardo

Stephen Day

Samir Rihani

Nicholas J Ekins-Daukes

Paul Nicholas Stavrinou

Mathieu Bellanger

Paul N Stavrinou

A semiconductor device has a layered structure. The semiconductor device includes a metallic layer of thickness 1-100 nm, with a thickness optimized to absorb light in a wavelength range of operation. The device further includes an adjacent semiconductor layer additionally adjacent to an ohmic electrical contact, wherein the interface between the metallic layer and the semiconductor layer is electrically rectifying and energy selective. The device further includes a reflective back surface positioned opposite to the semiconductor layer relative to incident light providing broadband reflection in the wavelength range of operation. The semiconductor layer includes a quantum well adjacent to the metallic layer, wherein the energy selectivity is provided by the quantum well allowing charge carrier tunneling from the metallic layer. The device further may include an additional anti-reflection dielectric layer deposited on the metallic layer that is configured to minimize reflection of light in the wavelength range of operation.

Energy selective photodetector

A ballistic carrier spectral sensor includes a photon absorption region to generate photo-generated carriers from incident light; a first potential barrier region adjacent the photon absorption region and having an adjustable height defining a minimum energy of the photo-generated carriers required to pass therethrough; a second potential barrier region having an adjustable height defining a minimum energy of the photo-generated carriers required to pass therethrough; a spillage well region disposed between the first potential barrier region and the second potential barrier region and configured to collect photo-generated carriers having an energy lower than that required to pass through the second potential barrier region; and a collection region adjacent the second potential barrier region and configured to collect carriers that cross the second potential barrier region. A total thickness of the first potential barrier region and the spillage well region is less than a mean free path of the photo-generated carriers.

Ballistic carrier spectral sensor

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 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 manufacturing a semiconductor light-emitting device comprises selectively etching a semiconductor layer structure () fabricated in a nitride materials system and including an aluminum-containing cladding region or an aluminum-containing optical guiding region (). The etching step forms a mesa (), and also exposes one or more portions of the aluminum-containing cladding region or the aluminum-containing optical guiding region (). The or each exposed portion of the aluminum-containing cladding region or the aluminum-containing optical guiding region () is then oxidized to form a current blocking layer () laterally adjacent to and extending laterally from the mesa. When an electrically conductive contact layer () is deposited, the current blocking layer () will prevent the contact layer () from making direct contact with the buffer layer ().

Semiconductor light-emitting device and a method of manufacture thereof

A method of growing a semiconductor layer structure comprises growing a first semiconductor layer and incorporating hydrogen into the first semiconductor layer. One or more further semiconductor layers are then grown over the first semiconductor layer to form a semiconductor layer structure. A selected portion of the first semiconductor layer is then annealed so as to change the electrical resistance of the selected portion of the first semiconductor layer. The electrical resistance of the one or more further semiconductor layers that have been grown over the first semiconductor layer is not significantly changed by the annealing step. The invention may be used, for example, to create a current aperture in a semiconductor layer within a semiconductor layer structure.

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Oxford, United Kingdom

Matthias Kauer