Embodiments of the invention include methods and devices for producing light by injecting electrons from
field emission cathode across a gap into nanostructured
semiconductor materials, electrons issue from a separate field emitter
cathode and are accelerated by a
voltage across a gap towards the surface of the nanostructured material that forms part of the
anode. At the
nanostructure material, the electrons undergo
electron-hole (e-h) recombination resulting in electroluminescent (EL) emission. In a preferred embodiment lighting device, a vacuum
enclosure houses a field emitter
cathode. The vacuum
enclosure also houses an
anode that is separated by a gap from said
cathode and disposed to receive electrons emitted from the cathode. The
anode includes
semiconductor light emitting nano structures that accept injection of electrons from the cathode and generate photons in response to the injection of electrons. External
electrode contacts permit application of a
voltage differential across the anode and cathode to stimulate
electron emissions from the cathode and
resultant photon emissions from the
semiconductor light emitting nanostructures of the anode. Embodiments of the invention also include the usage of nanostructured
semiconductor materials as phosphors for conventional planar LED and
nanowire array light emitting diodes and CFL. For the use in conventional planar LEDs, the nanostructures may take the form of
quantum dots, nanotubes, branched tree-like
nanostructure,
nanoflower, tetrapods, tripods, axial heterostructures nanowires hetero structures.