Electronic and optical properties of TiO2 and its polymorphs by Z-scan method

被引:17
作者
Divya, S. [1 ]
Nampoori, V. P. N. [1 ]
Radhakrishnan, P. [1 ]
Mujeeb, A. [1 ]
机构
[1] Cochin Univ Sci & Technol, Int Sch Photon, Cochin 682016, Kerala, India
关键词
excitons; reverse saturable absorption (RSA); excitonic nonlinearity; ANATASE; NONLINEARITY; RUTILE;
D O I
10.1088/1674-1056/23/8/084203
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
TiO2 is a material which has attracted considerable attention from the scientific community for its innumerable properties. TiO2 is known to exist in nature in three different crystalline structures: rutile, anatase, and brookite. Anatase and rutile TiO2 films have been widely characterized for their potential applications in solar cells, self-cleaning coatings, and photocatalysis. In the present report, the third-order nonlinear susceptibilities of TiO2 and its polymorphs, anatase, and rutile, prepared by the sol-gel technique followed by heat treatment are investigated using the Z-scan technique at a wavelength of 532 nm with a duration of 7 ns. Imaginary and real values of chi((3)) for amorphous, anatase, and rutile are also calculated and found to be 5 x 10(19) m(2)/V-2, 27 x 10(19) m(2)/V-2, 19 x 10(19) m(2)/V-2, respectively. It is found that the values of the optical constants of amorphous TiO2 after heat treatment vary considerably. It is assumed that this could be due to the variation in the electronic structure of TiO2 synchronous with the formation of its polymorphs, anatase, and rutile. Amorphous TiO2 is marked by the localization of the tail states near the band gap, whereas its crystalline counterparts are characterized by completely delocalized tail states.
引用
收藏
页数:5
相关论文
共 14 条
  • [1] The design, fabrication, and photocatalytic utility of nanostructured semiconductors: focus on TiO2-based nanostructures
    Banerjee, Arghya Narayan
    [J]. NANOTECHNOLOGY SCIENCE AND APPLICATIONS, 2011, 4 : 35 - 65
  • [2] Self-energy and excitonic effects in the electronic and optical properties of TiO2 crystalline phases
    Chiodo, Letizia
    Maria Garcia-Lastra, Juan
    Iacomino, Amilcare
    Ossicini, Stefano
    Zhao, Jin
    Petek, Hrvoje
    Rubio, Angel
    [J]. PHYSICAL REVIEW B, 2010, 82 (04)
  • [3] Optical nonlinearity of hybrid and nanocomposite materials prepared by the sol-gel method
    Gan, FX
    [J]. JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 1998, 13 (1-3) : 559 - 563
  • [4] VERY LARGE OPTICAL NONLINEARITY OF SEMICONDUCTOR MICROCRYSTALLITES
    HANAMURA, E
    [J]. PHYSICAL REVIEW B, 1988, 37 (03): : 1273 - 1279
  • [5] KOTELES ES, 1982, EXCITONS, P83
  • [6] Lima-de-Faris J, 1994, STRUCTURAL MINERALOG, P682
  • [7] Liu P. S., 2009, NONFERR METAL SOC, V19, P743
  • [8] Third-order optical nonlinearities in anatase and rutile TiO2 thin films
    Long, Hua
    Chen, Aiping
    Yang, Guang
    Li, Yuhua
    Lu, Peixiang
    [J]. THIN SOLID FILMS, 2009, 517 (19) : 5601 - 5604
  • [9] ELECTRONIC AND OPTICAL-PROPERTIES OF 3 PHASES OF TITANIUM-DIOXIDE - RUTILE, ANATASE, AND BROOKITE
    MO, SD
    CHING, WY
    [J]. PHYSICAL REVIEW B, 1995, 51 (19) : 13023 - 13032
  • [10] Nian Tan Yong, 2011, ISRN MAT SCI, V2011