TY - JOUR
T1 - Compositional tailored sol-gel SiO2-TiO2 thin films
T2 - Crystallization, chemical bonding configuration, and optical properties
AU - Yang, Li Lan
AU - Lai, Yi Sheng
AU - Chen, Jen S.
AU - Tsai, P. H.
AU - Chen, C. L.
AU - Chang, C. Jason
N1 - Funding Information:
The authors gratefully appreciate the financial support from the Industrial Technology Research Institute (ITRI) and the National Science Council of Taiwan, Republic of China (Grant No. NSC 92-2216-E-006-028). The authors would like to thank the Center for Micro/Nano Technology Research, National Cheng Kung University, Tainan, Taiwan, for equipment access and technical support. The authors are also indebted to the RBS analysis conducted by the Nuclear Science and Technology Development Center, National Tsing Hua University and the FTIR analysis instrument provided by Prof. Lien-Chung Hsu, Department of Materials Science and Engineering, National Cheng Kung University.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2005/11
Y1 - 2005/11
N2 - Thin films of SiO2-TiO2 composite oxides with various SiO2:TiO2 compositions were prepared by the sol-gel method, using tetraethylorthosilicate (TEOS) and titanium tetraisopropoxide (TTIP) as precursors. The composition, crystal structure, and chemical bonding configuration of the as-deposited and annealed SiO2-TiO2 thin films were analyzed using Rutherford backscattering spectrometry (RBS), glancing incident angle x-ray diffraction (GIAXRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Optical properties of the films were characterized by spectroscopic ellipsometry and ultraviolet-visible spectrophotometry. The Si/Ti ratios in the SiO2-TiO2 films agree with the TEOS/TTIP molar ratio in the sol-gel precursor. When the TEOS/(TEOS + TTIP) ratio is greater than 40%, the SiO2-TiO2 thin films remain amorphous (without formation of TiO2 crystalline phase) after annealing at temperatures as high as 700 °C. FTIR spectra indicate that the quantity of Si-O-Ti bonding can be maximized when the TEOS:TTIP in the precursor is 80%:20%. The refractive index of the SiO2-TiO2 films increases approximately linearly to the mixing ratio of TTIP/(TEOS + TTIP). However, SiO2-rich films possess higher ultraviolet-visible transmittance than the TiO2-rich films. The modification of microstructure and chemical bonding configuration in the SiO2-TiO2 films by the composition and its influence on the optical properties are discussed.
AB - Thin films of SiO2-TiO2 composite oxides with various SiO2:TiO2 compositions were prepared by the sol-gel method, using tetraethylorthosilicate (TEOS) and titanium tetraisopropoxide (TTIP) as precursors. The composition, crystal structure, and chemical bonding configuration of the as-deposited and annealed SiO2-TiO2 thin films were analyzed using Rutherford backscattering spectrometry (RBS), glancing incident angle x-ray diffraction (GIAXRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Optical properties of the films were characterized by spectroscopic ellipsometry and ultraviolet-visible spectrophotometry. The Si/Ti ratios in the SiO2-TiO2 films agree with the TEOS/TTIP molar ratio in the sol-gel precursor. When the TEOS/(TEOS + TTIP) ratio is greater than 40%, the SiO2-TiO2 thin films remain amorphous (without formation of TiO2 crystalline phase) after annealing at temperatures as high as 700 °C. FTIR spectra indicate that the quantity of Si-O-Ti bonding can be maximized when the TEOS:TTIP in the precursor is 80%:20%. The refractive index of the SiO2-TiO2 films increases approximately linearly to the mixing ratio of TTIP/(TEOS + TTIP). However, SiO2-rich films possess higher ultraviolet-visible transmittance than the TiO2-rich films. The modification of microstructure and chemical bonding configuration in the SiO2-TiO2 films by the composition and its influence on the optical properties are discussed.
UR - http://www.scopus.com/inward/record.url?scp=33645471402&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33645471402&partnerID=8YFLogxK
U2 - 10.1557/JMR.2005.0393
DO - 10.1557/JMR.2005.0393
M3 - Article
AN - SCOPUS:33645471402
VL - 20
SP - 3141
EP - 3149
JO - Journal of Materials Research
JF - Journal of Materials Research
SN - 0884-2914
IS - 11
ER -