钽掺杂二氧化钛薄膜的溶胶-凝胶法制备及光电性能调控

摘要

Ta-doped TiO2 films have been prepared on quartz substrate by sol-gel method following a post-annealed process in hydrogen to improve the electrical and optical properties.The crystal phases,microstructure,electrical and optical properties of TiO2:Ta films were analyzed by XRD,SEM,Hall effect measurement,UV-Vis spectrophotometry and ellipsometry.The results show that Ta5+ ion in TiO2 lattice greatly improves n-type conductivity of TiO2 films.The resistivity of Ta-doped TiO2 films decreased largely after post-annealing in hydrogen.The improved electrical properties of films may be attributed to lager grain size of films and the formation of oxygen vacancies.The Ta-doped TiO2 films with 8％ Ta concentration exhibited the he minimum resistivity of 7.95Ω · cm and the transmittance of about 75％ in the visible light region,making it a candidate of promising TCO materials.%用溶胶凝胶法在石英基板上制备不同钽掺杂浓度的二氧化钛薄膜,并采取后续氢气退火的方法改善其光电性能以用于TCO薄膜.采取SEM、XRD等测试手段观察薄膜的微观形貌、结晶性能及组成态,并利用四探针测试、可见光透过率测试和椭偏测试得出薄膜的电学和光学性能.结果表明掺杂钽元素以Ta5+形式存在于TiO2晶格中,大大提高了二氧化钛薄膜的n型导电性能,这是由于掺钽后费米能级向导带方向移动所致.氢气退火后二氧化钛晶粒尺寸变大且均匀,薄膜的结晶性能得到改善,并且由于引入了更高浓度的氧空位,导电性能得到明显的提升.最终获得了钽掺杂浓度为8％、电阻率为7.95Ω·cm、可见光区域的透过率约为75％的钽掺杂氧化钛薄膜,有潜力应用于透明导电薄膜生产领域.