The optical and electrical characteristics of ZnO: Al thin films prepared by Sol-Gel method

Abstract

The transparent conducting ZnO: Al thin films were synthesised by sol-gel method using zinc acetate dihydrate (Zn(CH3COO)2.2H2O), Al(NO3)3.9H2O, 2-methoxyethanol and MEA (monoethanolamine) as precursor, dopant agent, solvent and stabilizer, respectively. XRD patterns showed polycrystalline wurtzite structure of ZnO: Al films annealed at 500oC in air. The conductivity depends on environment annealling conditions, i.e the conductivity increases 103 times by vacuum annealing (10-3Torr). The minimum resistivity was Rsmin=372/ at 2% aluminum dopant. The transmittance of undoped and doped films were higher than 85%. Uniformity films were evaluated by SEM.