Optimization of the process for preparing Al-doped ZnO thin films by sol-gel method

Transparent and conducting Al-doped ZnO thin films with c-axis-preferred orientation were prepared on glass substrate via sol-gel route.The physical and chemical changes during thermal treatment were analyzed by TG-DSC spectra and the crystallization quality was characterized by XRD patterns.The optimized preheating and post-heating temperatures were determined at～420°C and～530°C,respectively.From thermodynamic and kinetics views,we investigated the mechanism of orientation growth with(002) plane parallel to the substrates.The surface morphologies of the films,post-heated at 420°C,450°C,530°C and 550°C,respectively,were observed by SEM micrographs.The film post-heated at 530°C shows a homogenous dense microstructure and exhibits the minimum sheet resistance of 140Ω/Sq.The visible optical transmittance of all the films is beyond 90%.In addition,the annealing treatment in vacuum can contribute greatly to the electrical conductivity.     

Investigations of ZnO thin films deposited by a reactive pulsed laser ablation

Highly transparent ZnO thin films were deposited at different substrate temperatures by pulsed laser deposition in an oxygen atmosphere.The thin films were characterized by various techniques including X-ray diffraction,scanning electron microscopy,optical absorption,and photoluminescence.We demonstrated that oriented wurtzite ZnO thin films could be deposited at room temperature using a high purity zinc target.Variable temperature photoluminescence revealed new characteristics in the band edge emission.The...