Preparation Of Novel TCO Materials By High Target Utilisation Sputtering(HiTUS)and Their Characterization

Transparent conducting oxides(TCOs)are very important materials in the semiconductor industry because of their excellent optical and electrical properties,and have been successfully applied to thin film photovoltaic solar cells,flat panel displays,touch screens and LED/OLED.The most widely used transparent conductive oxide material is indium tin oxide(ITO)because of its extremely low resistivity(10-4 ?·cm),high transmittance(>90%)in the visible region and high thermal stability.However,the indium resources on the surface of the earth are seriously insufficient and expensive.Therefore,it is extremely urgent to develop and prepare new transparent conductive oxides to replace ITO.In this work,two high-performance transparent conductive oxides thin films were successfully fabricated on the glass,quartzand Si substrates using a High Target Utilisation Sputtering system.Thereafter,the properties of these materials were analyzed and the specific conclusions are shown as follows:1.Nb doped Sn02 thin films(1)The content of Nb in the Nb doped SnO2 thin film were analyzed by adjusting the width of the purlin and the flow of oxygen,respectively.When the area ratio of the beam to the tin target was 3%and the oxygen flow rate was 4 sccm,hawse obtained the thin f1lm with the lowest resistivity of 4.2×10-3 ?·cm and adequate transmittance in visible region.The optimized content of Nb was 3.5 at.%.(2)All of the thin films were deposited at room temperature,and the crystallinity of the thin film was poor.As the annealing temperature increased,the light transmittance of the thin film in visible region gradually increased.The conductivity of thin film firstly increased and then decreased,and had the lowest resistivity when annealed at 250?.2.Ta doped SnO2 thin films(1)Investigate the photoelectric properties of the film by adjusting the ratio of Ar and O2.As the proportion of oxygen increased,the light transmittance of thin filmin visible region gradually increased,and the conductivity of the film decreased.When O2 was 1.5 sccm,the thin film had the best electrical properties.(2)The temperature-dependent Hall test of the sample showed that the resistivityof the film was reduced to a minimum of 2.O×10-3 ?·cm at the temperature of 280?.At the same time,as the annealing temperature increased,the light transmittance of thin film in visble region was significantely improved.After annealing at 480?,the average transmittance in the visible light range was increased up to about 91%.(3)In order to further improve the performance of the thin film,the substrate was heated to 250?C during the preparation process,and the as-deposited thin films were sannealed in a mixed atmosphere of H2+Ar for 30 min.the optimized annealing temperature was 280?.