A micro electron gun that is capable of extracting electrons from a semiconductor
utilizing a quantum size effect and that can be mounted individually for each of
pixels is disclosed, as well as a picture display apparatus using such electron
guns which is high in quantum efficiency, of high brightness and thin, as well
as methods of manufacture thereof. Conduction electrons from a n-type semiconductor
substrate (2) are accelerated under an electric field through a layer or
layers (4) of quantum size effect micro particles (3) formed on surfaces
of the n-type semiconductor substrate (2) and passed therethrough without
undergoing phonon scattering, so that they when arriving at an electrode (5)
may possess an amount of energy not less than the work function of the electrode
(5) and are thus allowed to spring out into a vacuum. Such a quantum size
effect micro particle (3) comprises a micro particle of a single crystal
semiconductor in a nanometer order having electron energy levels made so discrete
that no phonon scattering is brought about, and on its surface area an insulator
so thin that an electron is capable of tunneling therethrough.
