Electron-stimulated luminescence (ESL) is production of light by cathodoluminescence,[1][2][3][4] i.e. by a beam of electrons made to hit a fluorescent phosphor surface.
Experimental light bulbs that were made using this technology do not include magnetic or electrostatic means to deflect the electron beam.
Electrons emitted from a cathode strike the phosphor; the current returns through a transparent conductive coating on the envelope.
The system has a power supply providing at least 5kVDC to the light emitting device, and the electrons transiting from cathode to anode are essentially unfocused.
As of 2016 the cost is higher and claimed efficiency is less than half that of commercially available LED bulbs, although it is considerably better than that of traditional incandescent lamps.