掺氟二氧化锡基薄膜激光表面处理及其光电性能优化研究

发布时间：2018-08-25 11:18

【摘要】：掺氟二氧化锡(FTO)薄膜作为透明导电氧化(TCO)薄膜,因其化学性质稳定,可见光区具有高透光率以及良好的导电性等优点,被广泛的应用于太阳能电池、气敏传感器、液晶显示屏等领域。但由于传统工艺制备的FTO薄膜,其光电性能往往无法满足当前快速发展光电器件的需求,为此研究者们集中于对FTO薄膜进行后续处理的研究。本文在调研薄膜激光表面处理相关研究的基础上,提出基于聚对苯二甲酸乙二酯(PET)贴膜和金属Ti层复合两种方式的FTO薄膜激光表面处理方法,着重研究激光参数对薄膜表面形貌、晶体结构、光学性能以及电学性能的影响,获得了一些有意义的结果。1、采用532 nm波长的纳秒脉冲激光对贴附了PET膜的FTO薄膜进行表面处理,着重研究激光能量密度和扫描速度对FTO薄膜光电性能的影响。采用扫描电子显微镜、X射线衍射仪、紫外-可见分光光度计和四探针测试仪对FTO薄膜的表面形貌、晶体结构、透光率和方块电阻进行表征,并采用品质因子(FTC)对FTO薄膜的光电性能进行综合评估。实验结果表明,贴附PET膜不仅可以拓宽激光工艺参数,避免FTO薄膜受到损伤,而且可以使薄膜表面获得更好的退火效果。其中,当激光能量密度为1.2 J/cm2、扫描速度为10.0 mm/s时,薄膜的综合光电性能最佳。其在400~800 nm波段的平均透光率为82.0%,方块电阻为7.9Ω/sq,品质因子为1.7×10~( 2)Ω~( 1),相比原始FTO薄膜品质因子(1.1×10~( 2)Ω~( 1))提高了54.5%。2、采用直流磁控溅射法,在FTO薄膜表面复合金属Ti层制备Ti/FTO复合薄膜,研究了Ti层厚度对Ti/FTO薄膜光电性能的影响。结果发现,当Ti层厚度为10 nm时,复合薄膜的品质因子值最大,为1.3×10~( 2)Ω~( 1)。再利用532 nm波长的纳秒脉冲激光对优化制备的Ti/FTO薄膜进行表面处理,主要研究激光能量密度和线间距对复合薄膜形貌、结构和光电性能的影响。实验结果表明,采用适当的激光能量密度和线间距对薄膜进行表面处理,一方面激光对复合薄膜表面起到退火作用,促进了复合薄膜的晶粒生长、消除部分晶体缺陷;另一方面促使Ti层氧化成TiO_2层,最终使薄膜的综合光电性能得到提升。其中,当激光能量密度为0.8 J/cm2、线间距为20.0μm时,Ti层完全氧化成TiO_2层,此时激光退火效果最好,TiO_2/FTO复合薄膜的综合光电性能最佳。其中,在400~800 nm波段范围内平均透光率为83.4%,方块电阻为8.7?/sq,品质因子为1.9×10~( 2)Ω~( 1),相比单层FTO薄膜的品质因子(1.2×10~( 2)Ω~( 1))提高了58.3%。
[Abstract]:As a transparent conductive and oxidized (TCO) film, (FTO) thin film doped with fluorine has been widely used in solar cells and gas sensors because of its stable chemical properties, high transmittance and good conductivity in visible region. Liquid crystal display screen and other fields. However, the optoelectronic properties of FTO thin films prepared by traditional technology are often unable to meet the needs of the rapid development of optoelectronic devices. Therefore, researchers focus on the follow-up processing of FTO thin films. In this paper, based on the investigation of laser surface treatment of thin films, a laser surface treatment method for FTO thin films based on the composite of (PET) film and metal Ti layer is proposed. The effects of laser parameters on the surface morphology, crystal structure, optical properties and electrical properties of the films were studied. Some significant results were obtained. The nanosecond pulsed laser at 532 nm wavelength was used to treat the FTO films with PET films. The effects of laser energy density and scanning speed on the photoelectric properties of FTO thin films are studied. The surface morphology, crystal structure, transmittance and square resistance of FTO thin films were characterized by scanning electron microscope (SEM), UV-Vis spectrophotometer and four-probe tester. The quality factor (FTC) was used to evaluate the photoelectric properties of FTO films. The experimental results show that the attached PET film can not only widen the laser processing parameters and avoid the damage of the FTO film, but also can obtain better annealing effect on the surface of the film. When the laser energy density is 1.2 J / cm ~ 2 and the scanning speed is 10.0 mm/s, the comprehensive photoelectric properties of the films are the best. Its average transmittance at 400-800 nm band is 82.0, the square resistance is 7.9 惟 / sqand the quality factor is 1.7 脳 10 ~ (2) 惟 ~ (-1). Compared with the original FTO film's quality factor (1.1 脳 10 ~ (2) 惟 ~ (-1), the Ti/FTO composite film is prepared by DC magnetron sputtering. The effect of the thickness of Ti layer on the optical and electrical properties of Ti/FTO thin films was investigated. The results show that when the thickness of Ti layer is 10 nm, the quality factor of the composite film is the highest, which is 1.3 脳 10 ~ (2) 惟 ~ (-1). The surface of the optimized Ti/FTO thin films was treated with 532nm nanosecond pulsed laser. The effects of laser energy density and line spacing on the morphology, structure and optoelectronic properties of the composite films were studied. The experimental results show that the appropriate laser energy density and line spacing are used to treat the surface of the composite film. On the one hand, the laser annealing on the surface of the composite film can promote the grain growth of the composite film and eliminate some crystal defects. On the other hand, the Ti layer is oxidized into TiO_2 layer, and the comprehensive photoelectric property of the film is improved. When the laser energy density is 0.8 J / cm ~ 2 and the line spacing is 20.0 渭 m, the Ti layer is completely oxidized to TiO_2 layer, and the laser annealing effect is the best. The comprehensive photoelectric properties of TiO2 / FTO composite thin films are the best. The average transmittance is 83.4, the square resistance is 8.7 / sqand the quality factor is 1.9 脳 10 ~ (2) 惟 ~ (-1), which is 58.3% higher than that of the monolayer FTO film (1.2 脳 10 ~ (2) 惟 ~ (-1).
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2;TN249

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