Preparation And Performance Study Of Inorganic Thin Films On Substrate Of OLED

Organic Light Emitting Diode (OLED) is a new generation of flat panel display technology mainstream, which has a series of advantages, such as high brightness, high resolution, wide viewing angle, ultra-thin, ultra-light, and the simple preparation process. Indium tin oxide (ITO) film is an n-type wide band gap semiconductor oxide, which has a complex cube bixbyite structure, the band gap is 3.5eV, and with a high work function, so it is usually as a basic and important structure element of OLED-anode. Because of the unique nature of having a light-transmissive and electrically conductive, its performance will directly related to the performance quality of entire device,such as the emission luminance, stability, current density and so on. Based on this, in order to meet the requirements of the OLED anode, the ITO transparent conductive film combines a high visible light transmittance with high electrical conductivity should be prepared is the focus of this thesis.The well-known method of the ITO thin films development include spray pyrolysis, E-beam evaporation, sol-gel process, laser deposition, and RF magnetron sputtering, DC magnetron sputtering and pulsed magnetron sputtering.In this paper, transparent conductive indium tin oxide (ITO) films were prepared on flexible polyethylene terephthalate (PET) plastic substrate and quartz glass substrate by pulsed magnetron sputtering. The crystal phase structure of ITO films was investigated by X-ray diffraction (XRD) and surface morphology was observed by scanning electron microscope (SEM), we study the influence of sputtering power, sputtering time, substrate temperature and deposition pressure by digital four-probe tester and UV-Vis spectrophotometer on the ITO films, aimed at seeking the best balance between high transmittance and low sheet resistance though the changes in process parameters, to gain the excellent electric conductive and optical transmittance properties of ITO films, and compare on different substrates.In our paper, we study the influence of the sputtering power, the sputtering pressure, the sputtering time, the substrate temperature under the conditions of the target distance is 65mm, the substrate rotation speed is 10r/min, the dorsal low vacuum is 5×10-3Pa, the results show that the crystal preferred orientation of thin films on PET substrate is (222) crystal plane, with the increase of the substrate temperature, the average crystallite size is grows from 41.10nm to 43.97nm, and with the extension of sputtering time, the average crystallite size firstly increases and then decreases. The sheet resistance firstly decreases and then increases with the increase of sputtering pressure, both decreases with the extension of sputtering time and the rising of substrate temperature. The visible light transmittance decreases with the extension of sputtering time, and increases with the rising of substrate temperature, but not effects by the changing of sputtering pressure. Compared to the PET substrate, the films sputtered on quartz substrate has more higher density on surface, more light transmittance, better conductivity under same process parameters. The results prove that the requirements of properties of ITO films sputtering on two substrates as OLED anode are satisfied, and the expected goals of the subject are achieved.