Preparation Of Al-doped ZnO Conductor By Liquid-phase Method

The transparent electric conduction oxide compound thin films prepared for the first time since 1907 successfully,Already in the production, life each aspect obtained the widespread application. Because at present applies the widespread Sn-doped In₂O₃(ITO) electric conduction thin films production cost high, the stability is insufficient, therefore Al-doped ZnO electric conduction thin films already to become its best substitute. Al-doped ZnO (ZAO) although has the good electric conductivity, but the production craft quite is complex, realizes the industrialization production with difficulty. Therefore, whether found the method which simple, is easy to control to synthesize the Al-doped ZnO electric conduction ceramics target material, is the mass production Al-doped ZnO electric conduction thin film substitution at present the commonly used Sn-doped In₂O₃ electric conduction thin film key.Based on the present ZAO industrialization production present situation, the present paper used liquid phase method: The boiling reflux and the co-precipitation law prepares the ZAO powder . These two methods all have the technical process simply, condition temperate, is easy to control and so on the merit. Our main work and the achievement relate in detail as follows:First, separately selects Zn (NO3) 2andAl (N03) 3 systems, Zn (CH3COO) 2 and Al (NO3) 3 systems, ZnS04and Al2 (S04) 3 systems took the forerunner body, used the boiling reflux to success to prepare a series of dopings quantity different ZAO powder , and summarized in the end product through the repeated test the aluminum element content along with the forerunner body in the aluminum salt and the zinc salt density compared to the change rule, thus could in the very good control ZAO powder body the aluminum element content. We the sample which resulted in to the system have carried on the attribute, studied the different doping to measure the ZAO powder the appearance, the structure, the electricity nature. Through the change sample pH value, the calcining heat and the doping quantity observe the sample the block resistance value, obtains the conclusion: The block resistance increases along with the pH value but increases, reduces first after the calcining heat increases, reduces first after the doping quantity increases. According to the conclusion which obtains determined the boiling reflux prepares ZAO the powder forerunner body pH value to be supposed to control is the weak basicity, the calcining heat 500 °C 600 °C is better, best dopes the quantity nitrate is 4.67%, the nitrate preparation sample is friends with compared to the acetate preparation sample electric conductivity. The nitrate for the forerunner body fashion appearance is along with doping quantity increasing from the clavate change to theirregular accurate sphere, but take acetate as forerunner body then is dumbbell-shaped increases from the pure zinc oxide along with the doping quantity turns tiny granulated.Second, selects Zn (NO3) 2 and Al (NO3) 3 systems, ZnSO4 and Al2 (SO4) 3 systems took the forerunner body, used altogether the precipitation method to prepare a series of dopings quantity different ZAO powder , and summarized in the end product through the repeated test which prepared with this method the aluminum element content along with the forerunner body in the aluminum salt and the zinc salt density compared to the change rule, and discovered in forerunner body same also zinc salt and aluminum salinity compared to same situation in, two methods compared, the co-precipitation method doping effect was better. To this method preparation product appearance, the structure, the electricity nature carry on the research discovery, because responded we have joined other one kind of precipitating agent NH4HCO3.The precipitating agent density increased have been very many, the fineness ratio same system boiling reflux preparation sample reduced its grain after obviously to reduce greatly generally between 20 30nm, the appearance presented a more regular sphere, obtained the grain after for the nanometer level powder body, reducing which the grain passed through had the vital significance to the ZAO optical quality improvement.Third, we have conducted the optical quality research to two methods preparations sample, we determined the sample UV spectrum, the fluorescence spectrum separately, the findings had indicated, mixed Al in ZnO, was advantageous in the zinc oxide ultraviolet absorption, also along with doping quantity increasing, the absorption strength also increased along with it. Two kind of sides legal systems result in the ZAO fluorescence absorption band differs from, altogether precipitation method preparation sample granularity quite small, the fluorescence absorption band quite is obvious, the boiling reflux preparation sample granularity in a micron level, absorbs is not very obvious.Through massive experiments us to draw the conclusion, the fluid physiognomy may realize the aluminum element doping, and may in the accurate control product the aluminum element doping quantity, the method which uses compared to the predecessor simpler, also is easier to control, has provided the certain theory basis for the industrialization production. Through to the product attribute and the research, proved two methods preparations the product all has the good performance, co-precipitation preparation sample grain after in a nanometer level, besides has the better electricity nature.