Plessey Semiconductors Limited

Kevin Stribley

Jun-Youn Kim

Mohsin Aziz

John Shannon

Samir Mezouari

Abdul Shakoor

Ian Murray

Stuart Brodie

Sharon Farrens

Ian Daniels

Anwer Saeed

James Carswell

Reetta Griffiths

According to the first aspect of the disclosure, a method of forming a light emitting device array precursor is provided. The method comprises forming a first light emitting layer on a first substrate, forming an array of first light emitting devices from the first light emitting layer, each first light emitting device configured to emit light having a first wavelength. A first bonding layer is formed on the first light emitting layer. A second light emitting layer is formed on a second substrate, the second light emitting layer configured to emit light having a second wavelength different to the first wavelength. A second bonding layer is formed on the second light emitting layer. The second bonding layer is bonded to a handling substrate, followed by removing the second substrate from the second light emitting layer. A third bonding layer is formed on the second light emitting layer on an opposite side of the second light emitting layer to the handling layer. The first bonding layer is bonded to the third bonding layer and the handling substrate is removed from the second light emitting layer. An array of second light emitting devices is formed from the second light emitting layer, the array of second light emitting devices aligned relative to the array of first light emitting devices such that they are spaced apart from each other in a plane parallel to each of the first and second light emitting layers.

Light emitting array

A method of preparing a substrate for substrate bonding is provided. The method comprises: forming a recess in a substrate surface of the substrate, and forming a bondable dielectric layer on the substrate surface of the substrate. The bondable dielectric layer has a bonding surface on an opposite side of the bondable dielectric layer to the substrate surface, wherein the recess and the bondable dielectric layer define a dielectric cavity having a dielectric cavity volume. A plug is formed configured to make electrical contact to the substrate in the dielectric cavity volume. The plug has a plug volume which is less than the dielectric cavity volume, wherein the plug extends from the dielectric cavity beyond the bonding surface in a direction generally normal to the bonding surface. The plug is coined by compressing the substrate between opposing planar surfaces such that a contact surface of the plug is made co-planar with the bonding surface.

Substrate bonding

A light emitting diode is provided having a LED layer configured to emit pump light having a pump light wavelength from a light emitting surface, the LED layer comprising a plurality of Group III-nitride layers. A container layer is provided on the light emitting surface of the LED layer, the container surface including an opening defining a container volume through the container layer to the light emitting surface of the LED layer. A colour converting layer is provided in the container volume, the colour converting Got layer configured to absorb pump light and emit converted light of a converted light wavelength longer than the pump light wavelength. A lens is provided on the container surface over the opening, the lens having a convex surface on an opposite side of the lens to the colour converting layer. A pump light reflector laminate provided over the convex surface of the lens the pump light reflector laminate having a stop-band configured to reflect the pump light centred on a first wavelength.

Light emitting diode with improved colour purity

A light emitting diode (LED) precursor is provided. The LED precursor comprises a substrate (), an LED structure () comprising a plurality of Group III-nitride layers, and a passivation layer (). The LED structure comprises a p-type semiconductor layer (), an n-type semiconductor layer (), and an active layer () between the p-type and n-type semiconductor layers. Each of the plurality of Group III-nitride layers comprises a crystalline Group III-nitride. The LED structure has a sidewall () which extends in a plane orthogonal to a () crystal plane of the Group III-nitride layers. The passivation layer is provided on the sidewall of the LED structure such that the passivation layer covers the active layer. The passivation layer comprises a crystalline Group III-nitride with a bandgap higher than a bandgap of the active layer. The LED structure is shaped such that the sidewall of the LED structure is aligned with a non-polar crystal plane of each the Group III-nitride layers of the LED structure.

Light emitting diode precursor including a passivation layer

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Plymouth, United Kingdom

Kevin Stribley