SÍNTESIS DE ÓXIDOS CONDUCTORES TRANSPARENTES DE ÓXIDO DE ZINC DOPADO CON ALUMINIO POR COPRECIPITACIÓN QUÍMICA TRANSPARENT CONDUCTING OXIDE SYNTHESIS OF ALUMINIUM DOPED ZINC OXIDES BY CHEMICAL COPRECIPITATION

Aluminium doped zinc oxides (AZO) are promising replacements for tin doped indium oxides (ITO) but thin films show a wide range of physical properties strongly dependent on deposition process conditions. Submicrometric 1% aluminum doped zinc oxide ceramics (AZO) are examined, prepared by coprecipitation, from Zn(NO3)2 and Al(NO3)3 aqueous solutions, sintered at 1200°C and subsequently annealed in 10-16 atm controlled oxygen fugacity atmospheres, at 1000°C. Electrical resistivity diminishes by two orders of magnitude after two hours of annealing and the Seebeck coefficient gradually changes from -140 to -50 µV/K within 8 h. It is concluded that increased mobility is dominant over the increased carrier density, induced by changes in metal-oxygen stoichiometry.