From the viewpoint of application electroluminescence(EL)is especially useful in the technology of flat panel display(FPD). Among the six types of emission FPDs

inorganic electroluminesence(IEL)and organic electroluminescence(OEL)are especially promising because of their several attractive characteristics.But there are still some deficiencies in their behavior.The main problem is the lack of blue colored emission in inorganic EL and the lack of electron transport materials and stability in organic EL.But because of the compansatory properties of IEL and OEL

it is quite natural to develop their superiority and to minimize their inferiority.From this analysis

we are convinced that the heterogeneous junction made from organic and inorganic materials as well as the excitation with AC and DC sources may satisfy the above-metioned requirements.In inorganic EL layered optimization has been proposed and investigated carefully.The aim of that structure is to strengthen the effect of electron acceleration in phosphors by spatially separated addition of pure electron acceleration layer to the ordinary IEL layer.But in reality the energy of electrons before entering phosphor layer have already enough value to excite centers of luminescence in the visible region by direct impact excitation.Since these energetic electrons are accelerated not in vacuum but in solids

the luminescence generated by their bombardment is called Solid State CL or CL-like emission.Since ZnS is well known in EL and has also good ability to accelerate electrons

so that in this paper

we prepared the organic/inorganic heterojunction of MEH-PPV under AC electric field excitation which is similar to the photoluminescence of MEH-PPV.By studying the optical characteristics of the device

we found that the emission was induced by direct bombardment of the accelerated electrons from ZnS.So it comes from the solid state cathodoluminescence.