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.