Preparation And Properties Of New AC PDP Dielectric Protective Layers

Plasma display panel(PDP) has many advantages, such as high brightness, good color rendition, rich gray scale, fast response speed of moving picture, strong electric and magnetic immunity, thin thickness and so on. Until the beginning of this century, PDP has been considered to be one of the most promising alternatives to the traditional cathode ray tubes. However, the market share of PDP in the commercial FPD market is declining now. The most fundamental reason is owing to its higher power consumption and cost caused by the high driving voltages. It is found that improving discharge characteristics of dielectric protective layer can reduce the power consumption of alternating current plasma display panels(AC PDP). In order to reduce power consumption, this study focused on the dielectric protective layer of AC PDP, without increasing extra manufacturing cost and complexity of process. The fabricating technologies and discharge performances of four new dielectric protective materials have been discussed.1. The energy band structures of Al doped Mg O and Zn, Sn co-doped Mg O were investigated by using the first principle method, respectively. The secondary electron emission coefficients of the above two kinds of doped materials based on Auger neutralization and Auger deexcitation process were calculated according to Hagstrum theory. The calculated results showed that, both of the doped materials had smaller bandgap than pure Mg O, and their secondary electron emission coefficients were much larger than pure Mg O. By using these two kinds of doped materials as dielectric protective layers, it could effectively reduce the discharge voltages of AC PDP.2. The discharge test system was designed and built by ourselves, which consisted of driving power supply, vacuum system, charge and discharge module and discharge unit. The test system, which could simulate real discharge environment of AC PDP, was used to measure the discharge performance of new dielectric protective layers obtained in our experiments.3. Al doped Mg O powders were prepared using hydrothermal method. Then, Al doped Mg O dielectric protective layer was prepared on commercial front substrate(with Mg O protective layer) of AC PDP by spin coating technology. The influencing factors including reaction time, reaction temperature, degree of filling, molar ratio of Mg:Al:CO(NH2)2 were discussed. The test results showed that, the discharge performance was improved using MgxAl1-xO/Mg O double films as dielectric protective layer of AC PDP in contrast with conventional Mg O film. Under the pressure of 400 torr 10 % Xe-Ne, the minimum firing voltage was reduced by 11.2 %; the maximum firing voltage was reduced by 14.8 %; the maximum sustain voltage was reduced by 18.2 %; the minimum sustain voltage was reduced by 4.2 % and the disharge delay time was reduced by 15.8 %.4. Zn and Sn co-doped Mg O powders were prepared using coprecipitation method. Then, Zn and Sn co-doped Mg O dielectric protective layer was prepared on commercial front substrate of AC PDP by spin coating technology. The effects of Zn and Sn doping concentration, sintering temperature, molar ratio of Zn:Sn on morphology and crystal phase of the products were discussed. In contrast with conventional Mg O protective layer, the minimum firing voltage of Zn and Sn co-doped Mg O/Mg O double layer was reduced by 3.6 %; the maximum firing voltage was reduced by 13.2 %; the maximum sustain voltage was reduced by 11.7 %; the minimum sustain voltage was reduced by 12.5 % and the discharge delay time was reduced by 33.1 % under the pressure of 400 torr 10 % Xe-Ne.5. Polycrystalline lanthanum hexaboride(La B6) was printed on commercial front substrate of AC PDP by screen printing technology. This La B6/Mg O double dielectric protective layer could supply more priming electrons because of low work function of La B6. The effects of mesh size, ball milling time, content of La B6, sintering temperature on morphology, crystal phase of the products and transmission rate were discussed. Under the pressure of 400 torr 10 % Xe-Ne, the minimum firing voltage was reduce by 4.6 % and the discharge delay time was reduced by 15.1 % compared with pure Mg O layer.6. La B6 doped Mg O thin film was prepared on commercial front substrate of AC PDP by radio frequency magnetron sputtering method. The effects of La B6/(La B6+Mg O) mass ratio in the target and sputtering power on morphology, crystal phase of the products, transmission rate and discharge performance were discussed. The optimal preparation parameters were: mass ratio of La B6/(La B6+Mg O) 3 %, sputtering power 100 W. The test results showed that the discharge performance was greatly improved using(Mg O-La B6)/Mg O double films as dielectric protective layer in contrast with conventional Mg O film. Under the pressure of 400 torr 10 % Xe-Ne, the minimum firing voltage of(Mg O-La B6)/Mg O was reduce by 29.6 %; the maximum firing voltage was reduced by 27.3 %; the maximum sustain voltage was reduced by 31 %; the minimum sustain voltage was reduced by 33 % and the discharge delay time was reduced by 14.1 %, respectively.