氢气氛退火对掺钛氧化锌薄膜光电性能的影响

Effect of hydrogen atmosphere annealing on the photo-electronic properties of Ti-doped zinc oxide thin films

为研究有氧溅射和氢气氛退火对TZO薄膜的光电性能的影响,采用射频磁控溅射法,以掺钛(2 at%)氧化锌为靶材,在石英衬底上溅射掺钛氧化锌(TZO)薄膜。在溅射过程中,往溅射室通入不同流量(0,6,10,15 sccm)的氧气,再将制备的TZO薄膜在氢气氛中退火,用XRD测试薄膜的晶体结构,用紫外分光光度计测量光学透过率并计算其光学带隙,用Hall效应分析仪测试表征薄膜的电性能参数。测试结果表明,在不同流量的氧气氛下溅射的TZO薄膜其光学透过率变化较小,但其电导率随氧气流量的升高而显著下降。氢气氛退火对薄膜样品的光学和电学性能均有较大的影响。对溅射过程中通入流量为15sccm氧气所制备的TZO薄膜,比较该样品经氢气氛退火前后的光学和电学性能参数,结果发现其可见光波段(400～760 nm)的平均透过率由84.9%提高到91.6%,其电阻率由1.16×10~2Ω·cm降到7.46×10^(-2)Ω·cm,其载流子浓度和迁移率分别由-3.32×10^(16)cm^(-3)和1.63 cm^2/(V·s)增加到-2.73×10^(19)cm^(-3)和3.07 cm^2/(V·s)。

In order to study the effect of aerobic sputtering and hydrogen atmosphere annealing on the photo-electric properties of the Ti-doped zinc oxide(TZO)thin films,the TZO thin films were sputtered on quartz substrates by radio frequency magnetron sputtering method using zinc oxide doped with 2 at%of titanium as its target.During the sputtering process,different flow rates of oxygen(0,6,10,15 sccm)were introduced into the sputtering chamber,and then the prepared TZO thin films were annealed in a hydrogen atmosphere.The crystal structure of the TZO thin film was characterized by XRD.The optical transmittance spectra of the TZO thin films were measured by a UV spectrophotometer,and the optical bandgaps of the films were calculated from the optical transmittance spectra.The parameters of electrical properties of the films were measured by a Hall Effect analyzer.The experimental results showed that the TZO thin films sputtered at different oxygen flow rates had little effect on their optical transmittances,however,their conductivities decrease significantly with increasing of oxygen flow rates.The hydrogen atmosphere annealing has a great influence on the optical and electrical properties of the TZO thin films.For the TZO film prepared by sputtering at an oxygen flow rate of 15 sccm,after comparing the optical and electrical parameters of this as-grown sample with those of the sample annealed in hydrogen atmosphere,it had been found that its optical transmittance increased from 84.9%to 91.6%,its resistivity decreased from 1.16×10 2Ω·cm to 7.46×10-2Ω·cm,its carrier concentration and mobility increased from-3.32×10 16 cm-3 and 1.63 cm 2/(V·s)to-2.73×10 19 cm-3 and 3.07 cm 2/(V·s),respectively.