Abstract: A light emitting diode device comprising: a plurality of nanowires or nanopyramids grown on a graphitic substrate, said nanowires or nanopyramids having a p-n or p-i-n junction, a first electrode in electrical contact with said graphitic substrate; a light reflective layer in contact with the top of at least a portion of said nanowires or nanopyramids, said light reflective layer optionally acting as a second electrode; optionally a second electrode in electrical contact with the top of at least a portion of said nanowires or nanopyramids, said second electrode being essential where said light reflective layer does not act as an electrode; wherein said nanowires or nanopyramids comprise at least one group III-V compound semiconductor; and wherein in use light is emitted from said device in a direction substantially opposite to said light reflective layer.

Abstract: A device, such as a light-emitting device, e.g. a laser device, comprising: a plurality of group III-V semiconductor NWs grown on one side of a graphitic substrate, preferably through the holes of an optional hole-patterned mask on said graphitic substrate; a first distributed Bragg reflector or metal mirror positioned substantially parallel to said graphitic substrate and positioned on the opposite side of said graphitic substrate to said NWs; optionally a second distributed Bragg reflector or metal mirror in contact with the top of at least a portion of said NWs; and wherein said NWs comprise aim-type doped region and a p-type doped region and optionally an intrinsic region there between.

Abstract: A composition of matter comprising: a plurality of group III-V nanowires or nanopyramids epitaxially grown on a polycrystalline or single-crystalline graphene layer, said graphene layer being directly supported on a crystalline substrate such as a group III-V semiconductor, sapphire, SiC or diamond substrate, wherein the epitaxy, crystal orientation and facet orientations of said nanowires or nanopyramids are directed by the crystalline substrate.

Abstract: A process for growing nanowires or nanopyramids comprising: (I) providing a graphitic substrate and depositing AlGaN, InGaN, AlN or AlGa(In)N on said graphitic substrate at an elevated temperature to form a buffer layer or nanoscale nucleation islands of said compounds; (II) growing a plurality of semiconducting group III-V nanowires or nanopyramids, preferably III-nitride nanowires or nanopyramids, on the said buffer layer or nucleation islands on the graphitic substrate, preferably via MOVPE or MBE.

Abstract: A composition of matter comprising: a graphene layer carried directly on a sapphire, Si, SiC, Ga2O3 or group III-V semiconductor substrate; wherein a plurality of holes are present through said graphene layer; and wherein a plurality of nanowires or nanopyramids are grown from said substrate in said holes, said nanowires or nanopyramids comprising at least one semiconducting group III-V compound.

Abstract: A composition of matter comprising: a graphitic substrate optionally carried on a support, a seed layer having a thickness of no more than 50 nm deposited directly on top of said substrate, opposite any support; and an oxide or nitride masking layer e directly on top of said seed layer; wherein a plurality of holes are present through said seed layer and through said masking layer to C said graphitic substrate; and wherein a plurality of nanowires or nanopyramids are grown from said substrate in said holes, said nanowres or nanopyramids comprising at least one semiconducting group III-V compound.

Abstract: A composition of matter comprising a film on a graphitic substrate, said film having been grown epitaxially on said substrate, wherein said film comprises at least one group III-V compound or at least one group II-VI compound.

Abstract: A composition of matter, in particular a photovoltaic cell, comprising: at least one core semiconductor nanowire on a graphitic substrate, said at least one core nanowire having been grown epitaxially on said substrate wherein said nanowire comprises at least one group III-V compound or at least one group II-VI compound or at least one group IV element; a semiconductor shell surrounding said core nanowire, said shell comprising at least one group III-V compound or at least one group II-VI compound or at least one group IV element such that said core nanowire and said shell form a n-type semiconductor and a p-type semiconductor respectively or vice versa; and an outer conducting coating surrounding said shell which forms an electrode contact.

Abstract: The invention relates to a semiconductor device, e.g. for the emission or absorption of light, preferably in the deep ultraviolet (DUV) range. The device, e.g. a resonant cavity light emitting diode (RCLED) or a laser diode, is formed from: a substrate layer (302), preferably comprising a distributed Bragg reflector (DBR); a graphitic layer (304); and at least one semiconductor structure (310), preferably a wire or a pyramid, grown on the graphitic layer, with or without the use of a mask layer (306). The semiconductor structure is constructed from at least one III-V semiconductor n-type doped region (316) and a hexagonal boron-nitride (hBN) region (312), preferably being p-type doped hBN.

Abstract: A composition of matter comprising at least one nanostructure grown epitaxially on an optionally doped ?-Ga2O3 substrate, wherein said nanostructure comprises at least one group III-V compound.

Abstract: A composition of matter comprising at least one nanowire on a graphitic substrate, said at least one nanowire having been grown epitaxially on said substrate, wherein said nanowire comprises at least one group III-V compound or at least one group II-VI compound or comprises at least one non carbon group (IV) element.

Abstract: A process for growing nanowires or nanopyramids comprising: (I) providing a graphitic substrate and depositing AlGaN, InGaN, AlN or AlGa(In)N on said graphitic substrate at an elevated temperature to form a buffer layer or nanoscale nucleation islands of said compounds; (II) growing a plurality of semiconducting group III-V nanowires or nanopyramids, preferably III-nitride nanowires or nanopyramids, on the said buffer layer or nucleation islands on the graphitic substrate, preferably via MOVPE or MBE.

Abstract: A composition of matter comprising at least one nanostructure grown epitaxially on an optionally doped ?-Ga2O3 substrate, wherein said nanostructure comprises at least one group III-V compound.

Abstract: A composition of matter comprising a film on a graphitic substrate, said film having been grown epitaxially on said substrate, wherein said film comprises at least one group III-V compound or at least one group II-VI compound.

Abstract: A composition of matter, in particular a photovoltaic cell, comprising: at least one core semiconductor nanowire on a graphitic substrate, said at least one core nanowire having been grown epitaxially on said substrate wherein said nanowire comprises at least one group III-V compound or at least one group II-VI compound or at least one group IV element; a semiconductor shell surrounding said core nanowire, said shell comprising at least one group III-V compound or at least one group II-VI compound or at least one group IV element such that said core nanowire and said shell form a n-type semiconductor and a p-type semiconductor respectively or vice versa; and an outer conducting coating surrounding said shell which forms an electrode contact.

Abstract: A composition of matter comprising: a graphitic substrate optionally carried on a support, a seed layer having a thickness of no more than 50 nm deposited directly on top of said substrate, opposite any support; and an oxide or nitride masking layer e directly on top of said seed layer; wherein a plurality of holes are present through said seed layer and through said masking layer to C said graphitic substrate; and wherein a plurality of nanowires or nanopyramids are grown from said substrate in said holes, said nanowres or nanopyramids comprising at least one semiconducting group III-V compound.

Abstract: A process for growing nanowires or nanopyramids comprising: (I) providing a graphitic substrate and depositing AlGaN, InGaN, AlN or AlGa(In)N on said graphitic substrate at an elevated temperature to form a buffer layer or nanoscale nucleation islands of said compounds; (II) growing a plurality of semiconducting group III-V nanowires or nanopyramids, preferably III-nitride nanowires or nanopyramids, on the said buffer layer or nucleation islands on the graphitic substrate, preferably via MOVPE or MBE.

Abstract: A composition of matter comprising a film on a graphitic substrate, said film having been grown epitaxially on said substrate, wherein said film comprises at least one group III-V compound or at least one group II-VI compound.

Abstract: A composition of matter, in particular a photovoltaic cell, comprising: at least one core semiconductor nanowire on a graphitic substrate, said at least one core nanowire having been grown epitaxially on said substrate wherein said nanowire comprises at least one group III-V compound or at least one group II-VI compound or at least one group IV element; a semiconductor shell surrounding said core nanowire, said shell comprising at least one group III-V compound or at least one group II-VI compound or at least one group IV element such that said core nanowire and said shell form a n-type semiconductor and a p-type semiconductor respectively or vice versa; and an outer conducting coating surrounding said shell which forms an electrode contact.

Abstract: A composition of matter comprising: a graphitic substrate optionally carried on a support; a seed layer having a thickness of no more than 50 nm deposited directly on top of said substrate, opposite any support; and an oxide or nitride masking layer directly on top of said seed layer; wherein a plurality of holes are present through said seed layer and through said masking layer to said graphitic substrate; and wherein a plurality of nanowires or nanopyramids are grown from said substrate in said holes, said nanowires or nanopyramids comprising at least one semiconducting group III-V compound.