Fe掺杂TiO2纳米多孔薄膜的制备及光学性质研究

PREPARATION AND OPTICAL PROPERTIES OF THE Fe-DOPED POROUS TIO2 THIN FILMS

  • 摘要: 将Fe掺杂的TiO2-PEG 2 000溶胶旋涂在玻璃基底上,经过退火处理后得到Fe掺杂TiO2纳米多孔薄膜。用场发射扫描电子显微镜、X-射线衍射仪、紫外可见分光光度计和荧光光谱仪分别对样品的形貌、物相结构以及光学特性进行了表征。结果表明:制备的Fe掺杂TiO2纳米多孔薄膜,表面微孔分布均匀,其光吸收边随着Fe掺杂浓度的增加发生了显著红移,当掺杂量为0.15 M时红移量达到最大,约150 nm,说明Fe掺杂可减小TiO2纳米多孔薄膜的光学带隙。此外,样品的光致发光测试结果显示,随着Fe掺杂浓度的逐渐增加,样品的发光强度呈先抑后扬的变化趋势,这说明Fe掺杂浓度对TiO2纳米薄膜光生电子-空穴对的复合几率亦有很大影响,只有当Fe掺杂浓度为0.10 M时,TiO2薄膜的光生载流子复合几率最低。可见,这是一个益于改善TiO2纳米多孔薄膜光电转换性能的优化参数。

     

    Abstract: Porous Fe-doped TiO2 thin films we prepared on the glass by spin coating of the TiO2 sol including the polyethylene glycol 2000(PEG 2000) and Fe ions.The morphology,crystalline structure,and optical properties of the as-grown specimens were characterized by using of the scanning probe microscopy,X-ray diffraction,UV-VIS transmittance spectroscopy,and photoluminescence(PL) measurement,respectively.It was found that the Fe-doped TiO2 thin films exhibited porous structure with well-distributed pores,a red shift of the absorption edge occurred with the increase of Fe-doped concentration.And the maximum red shift was 150 nm as the concentration of Fe is 0.15 M,indicating that the Fe doping could reduce the band-gap of TiO2.Additionally,the recombination rates of the excitation were strong dependant on the doping concentration of Fe,for instance,the photoluminescence signal of the Fe-doped TiO2 thin films firstly decreases and then increases with the increasing of doping,and reaches its minimum in 0.10 M.Obviously,the optimized parameter would be beneficial to improve the photoelectric performances of porous TiO2 thin films.

     

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