| Electric field induced luminescence (EFIL) is a branch of luminescence in which the excitation modes are simple but the physical content is very rich. The excitation may be obtained by different ways and relaxation of their excited states leads to luminescence. EFTL is a phenomenon of direct transformation of electrical energy into optical energy. EFIL may be realized in powder, thin film and single crystals or in inorganic and organic materials. They all are solid materials and provide excellent convenience for applications. The direct application of EFTL is flat panel displays. It has several preferences, emissive, wide view angle, quick response, wide working temperature range, high pixel resolution, anti-strike, long life, less number of fabrication process etc. All these properties are better than plasma display FED and LC.In chapter 2 and 3 we introduced the development and problems in inorganic and organic electroluminescence(IEL and OEL).In chapter 4 we utilize the simple static properties of inorganic material to form complex with organic material. The first method is to modify the cathode by LiF in fabricating ITO /Alq3/LiF/Al; The intensity of luminescence is increased in 7-8 folds and the efficiency is doubled. LiF is a good insulator. The high electric field makes the barrier very thin. At this time the electron injection property is not influenced. But the hole is blocked. We studied further the mixture of Alqs and LiF in the form of solution and thin film and found that the luminescent spectrum is changed. This phenomenon arises perhaps due to ionic character of Li or F.The second method is to insert MgF between two layers of organic materials. When these organic materials meet each other they may form exciplex which introduce new spectral lines and reduce original ones. We compared the spectra of samples ITO/TVK:TPB/Alg3/Al and ITO/PVK:TPB/MgF/Alg3/Al. We found that the spectrum from exciplex is much reduced. MgF plays the role of segregation.The third method is to enhance the OEL by means of making complex with n-VI compounds. El-VI compounds are very stable and possessing higher electron mobility than organic materials. On the other hand organic materials may be operated at lowervoltage and is eligible to get blue color luminescence. These two kinds of materials are mutual compensatory. We prepared the samples ZnO/ppv and ZnS/ppv.The light intensity obtained is enhanced in 7-10 fold. By analyzing their energy offset on the interfaces, we found that the introduction of II-VI compounds replaces the original steep barrier with ladder-like barriers. The injection probability becomes the production of two injection probabilities through lower barriers and become larger than the original one.In chapter 5 we want to utilize the deeper ,dynamical (in addition of static) properties of semiconductor to reinforce the luminescence of OEL. This is possible because the electric field intensities in IEL and OEL are similar. If we prepare heterojunction from them, we may anticipate the coexistence of both kinds of EL. In the study on IEL we have proposed the scheme of layered optimizations. Here we simply change the inorganic luminescent layer with organic material, then we can get luminescence with two peaks. Since the carrier mobility in organic materials is very low, no collision excitation is possible. The short wavelength peak is due to direct bombardment by electrons from SiC>2. We name this luminescence as cathodoluminescence - like (CL-Like ) emission or solid state cathode luminescence because the energized electrons are accelerated in solid instead of in vacuum. The peak at shorter wave length side is assigned to be the electronic transitions between LUMO and HOMO and that at longer wavelength is considered to be originated from excitons. To prove this assignment we draw support from study on ionization of excited luminescent centers in inorganic materials. We really observed the same behavior.Further we prepared two samples of the structures ITO/OEL/SiO2/Al and irO/SiO2/OEL/A...
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