Sciencemadness Discussion Board

Aluminum Doped Zinc Oxide Films

SupaVillain - 16-8-2015 at 18:19


If I have a glass substrate that has zinc oxide as its outermost layer, and I dip it into these chemical baths described below, will I get the same effect or will the chemical bath just react with my last zinc oxide film?





"Pure zinc oxide films were deposited on glass substrates (microscope slides) by alterna-tively dipping into 0.1 M ammonium zincate [(NH4)ZnO2]bath kept at room temperature and hot water maintained near the boiling point. The glass substrate was cleaned, before deposition, by chromic acid followed by distilled water rinse and ultrasonic cleaning with acetone and alcohol. The cleaned substrate was tightly held in a holder so that only a requisite area for film deposition was exposed. Thus, the area for film deposition could be easily varied by adjusting the holder arrangement. The ammonium zincate bath, used for deposition, was prepared by adding ammonium hydroxide (∼25% pure ammonia solution; Merck, Mol. Wt. 17.03 g/mol, density 0.91) to an aqueous solution of zinc acetate dihydrate [Zn(CH3COO)22H2O]. The pH of the zincate solution was 10.80. pH measurement was carried out in a systronics pH meter (Model 335). Aluminium doping was carried out by adding hexahydrate aluminium chloride (AlCl3·6H2O, Merck) in ammonium zincate bath."

deltaH - 17-8-2015 at 01:57

While attempting to prepare alkali zincates (the thread is somewhere here), I discovered that zinc oxide powder was stubbornly inert at dissolving in bases. However, I found the same zinc oxide quickly reacted with acid and then could be dissolved in excess base via a precipitation of the much more reactive zinc hydroxide. Since this solution is only weakly basic, I would say first heat treat you zinc oxide coated glass, then dip, it should be fine. No guarantees of course!