Study On The Preparation And Properties Of Al Doped ZnO Transparent Conductive Film With High Infrared Reflectance

In recent years, with the development of semiconductor, computer, LCD display, organic electroluminescent display, plasma display and solar energy industry, transparent conductive oxide thin films have developed rapidly. Indium tin oxide (ITO) is one of the transparent conductive films that have been widely applied. But In is a rare and toxic element. So it is particularly important to find indium free transparent conductive film. Al doped ZnO thin films (AZO) become one of the most promising materials. Because it has similar photoelectric properties to ITO films, and it is plentiful, nontoxic and stable in H plasma.In this paper, AZO thin films were deposited on glass substrates by pulsed laser deposition (PLD). The phase structure of thin film, surface morphology, electrical and optical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), photoelectron spectroscopy (XPS), four-point probe and spectrophotometerAccording to the requirements of PLD apparatus, AZO ceramic targets were prepared by the method of atmospheric pressure sintering. And the effect of the target quality on the performance of AZO thin films. The results show that the AZO films deposited from the targets sintered at 1200℃ for 3 hours present good electrical and optical properties.The effects of Al2O3 content in the target, substrate temperature and deposition time on the quality, electrical and optical properties of AZO films were systematically investigated, and we obtained outstanding AZO films after optimizing the target composition and deposition parameters. The AZO films with excellent properties were deposited from the target with 2 wt% Al2O3 content for 60 min under the conditions of the laser energy is 250 mj, the distance of the target to the substrate is 60 mm and the temperature of the substrate is 150℃。The thin film has a relatively large grain size which is around 32.2 nm. Its resistivity is as low as 1.5×10-4 Ω·cm and the average near infrared reflectance in the range of 1000-2500 nm is as high as 55.3%.