The dispute between molecular and band theory arose from the very beginning of extended study of (organic) electroluminescence. We investigated the layered optimization scheme for inorganic electroluminescence and (obtained)the experience of acceleration ability of SiO

2

being greater than 10eV

which is large enough to excite an (electroluminescence) materials. We discovered solid state cathodoluminescence by means of this frame and used the newly discovered solid state cathodoluminescence to study the blue spectral shift when the applied voltage is increased. We found three different kinds of spectra in three consecutive intervals of applied voltage. We found that the field ionization of excitons plays a very important and critical role in this blue shift. The switching on of short wavelength emission (recombination radiation) starts only after the beginning of this field ionization. The exciton emission obeys molecular theory and the recombination obeys energy band theory. Thus their demarcation is the appearance of field ionization of excitons. Since the ionization is changing with electric field continuously

there is a region of (coexistence) of these two processes.