Study On Preparation At Low Temperature And Photoelectric Properties Of AZO Films

Transparent conducting oxides(TCO)have been widely used in optoelectronics devices due to their high transmittance in the visible region and low resistivity.Among them,aluminum doped zinc oxide(ZnO:Al,AZO)has become a research hotspot and has a great potential in the field of application due to its a series of advantages such as rich raw materials,non-toxicity,the excellent stability in high temperature and hydrogen plasma environment.It is believed that relatively high deposition temperature or post annealing is indispensable to gain the AZO films with excellent crystalline quality.However,high deposition temperature or post annealing limits the application of AZO thin films in flexible devices,so it is important to prepare AZO thin films at low temperatures.Besides,the preparation of AZO thin films at low temperatures and their growth kinetics are not systematic.In this paper,AZO thin films with preferred orientation and good quality were prepared by radio frequency magnetron sputtering at low temperature,and the growth dynamics was preliminarily explored.Firstly,the deposition parameters for obtaining preferred orientation structure at low temperature was preliminarily explored.The effects of Argon flow rate on the morphology,microstructure,optical,electrical and photoluminescence properties of the samples were systematically studied.The AZO film with resistivity 1.39×10-3 ?·cm,sheet resistance 8.2?/sq and 84.2%average visible transmittance was prepared at 44 sccm for 30 min.Secondly,the effects of deposition time and sputtering power on the morphology,microstructures,optical,electrical and photoluminescence properties of AZO films were systematically studied.The photoelectric properties of AZO films grown at low temperature are mainly influenced by their crystalline structure.In this paper,the evolution model of microstructures related to the growth stage is proposed.The effects of power on the dense columnar structure and photoelectric properties are studied.The results indicated that higher power was conducive to the earlier appearance of dense columnar structures.When the power is higher,the film thickness decreases when the appearance of dense columnar structure.Finally,the AZO film with resistivity 1.14×10-3 ?·cm,sheet resistance 6.07 ?/sq and 83.2%average visible transmittance was prepared at 210 W for 30 min.According to the XRD results and XPS analysis,the decreased doping content of Al and the appearance of Al2O3 have a significant influence on the deterioration in electrical properties of the sample deposited at 240 W.