An energy gap in the unzipped end of the carbon nanotube may be less than an energy gap in a region of the carbon nanotube outside of the unzipped end region.

The present inventors describe examples of such fibres that guide light by virtue of a true photonic band-gap in a hollow core region having a boundary at the interface between the hollow core and a photonic band-gap cladding.

In one form, the cyclometalated iridium complex includes bandgap lowering ligands, for example aryl quinoline.

In another form, the cyclometalated iridium complex includes bandgap widening ligands, for example aryl triazole.

In particular, the present inventors describe hollow core optical fibres, for example hollow core photonic band-gap optical fibres.

A wide bandgap semiconductor material comprised of Silicon carbide containing a predetermined portion of germanium.

In the light-emitting element, the second substance is a substance having an energy gap (or triplet energy) larger than the first substance.

The first dopant element has an oxide presenting a high bandgap in its electronic structure, and is preferably A1 and/or Mg.

The oxide layer contains a common element to the oxide semiconductor layer and has a large energy gap than the oxide semiconductor layer.

The size of the energy gap, or band gap, between these two bands in diamond is 5.5 electron volts, about twice as much energy as present in a visible-light photon and five times as large as the band gap in silicon.

Graphene particulates having narrow widths, on the order of 100 nm or less, can be produced having band gap properties suitable for use in a variety of electrical applications.

With his brother, Heinz London, he developed the first successful phenomenological theory (1935) of superconductivity, which crucially depends on the existence of an energy gap in electron states.

The Ga-assisted GaAsP nanostructures can be fabricated with a band gap in the range 1.6 to 1.8 eV (e.g. at and around 1.7 eV).