Preparation And Stability Investigation On MZO (Molybdenum Doped Zinc Oxide) Thin Films

Transparent conductive oxide film?TCO?,for its lower resistivity,higher visible light transmittance and high reflectivity in the infrared region,is widely used in various areas,such as solar cells,flat panel display and touch screen.Currently,the most utilized TCO are tin-doped indium oxide?ITO?due to its excellent performance.However,ITO are facing limited use because the scarcity of metal In and easy of diffusion into the organic layers in organic light emitting diodes?OLED?,which suppress its resistivity and transmittance.Under this scenario,doped ZnO films become promising candidates to replace ITO because they are inexpensive,abundant,nontoxic and exhibiting comparable optical and electrical properties to ITO films.Recently,Mo-doped ZnO?MZO?films draw significant attentions,because of the high valence of Mo which if replacing Zn will introduce much more free electrons into the system.Therefore,fewer dopants are required for larger carrier concentration.MZO thin films have been deposited by dual-target magnetron sputtering with the direct current?DC?target and the ratio frequency?RF?target sputtering.The lattice structure and surface morphology information of the films have been obtained by X-ray diffraction?XRD?and scanning electron microscope?SEM?.The optical and electrical properties of MZO films have been measured with Hall effect measurements and UV-visible spectrophotometer.Effect of Ar pressure,Mo target position and substrate on the properties of MZO films have been investigated.When the Ar pressure is 0.2 Pa,the angle of Mo target and horizontal is 10°,MZO film prepared at sapphire substrate have the lowest resistivity which is 2.42×10^-3?·cm.Correspondingly the carrier concentration is1.059×10²⁰ cm^-33 and the hall mobility is 24.38 cm²·V^-1·s^-1.In addition,the transmittance of the film is 93.82%throughout the visible light region.In the stability study of the MZO films,effect of temperature change and humidity on the properties of MZO films have been investigated.With the increase of exposure time in water,the stability of the films gradually deteriorate;and with the increase of cycles of the temperature change,the stability of MZO films also deteriorate.