Band-gap energy estimation from diffuse reflectance measurements on sol-gel and commercial TiO2: a comparative study
Band-gap energy estimation from diffuse reflectance measurements on sol-gel and commercial TiO2: a comparative study
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DOI：
10.1007/s10971-011-2582-9
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发表时间：
2012-01-01
影响因子：
2.5
通讯作者：
Gomez, Ricardo
中科院分区：
文献类型：
--
作者：
Lopez, Rosendo;Gomez, Ricardo
报道了由溶胶-凝胶法制备的TiO 2粉末与商业TiO 2粉末、纳米粉末、散装粉末和P25的紫外-可见反射光谱估计的带隙能量的比较。从光学吸收光谱获得的实验结果报告为所有的二氧化钛样品。使用图形表示来计算E-g：吸光度与λ; F（R）与E;（F（R）h nu）（n）与E，其中对于间接允许跃迁n = A1/2，对于直接允许跃迁n = 2。从结果中可以看出，E-g根据用于图示的方程而强烈变化。在E-g的差异高达0.5 eV的相同的半导体取决于所选择的过渡进行了观察。用一般方程α（h nu）a/千分之B（h nu-E-g）（n）（其中α与F（R）相似）和间接允许跃迁，得到了所研究的四种半导体中E-g的精确估计。
A comparison of the band gap energy estimated from UV-vis reflectance spectra of TiO2 powders prepared by sol-gel route versus commercial TiO2 powders, nanopowder, bulkpowder and P25 is reported. The experimental results obtained from the optical absorption spectra were reported for all the TiO2 samples. Graphic representations were used to calculate E-g: absorbance versus lambda; F(R) versus E; (F(R) h nu)(n) versus E, with n = A1/2 for an indirect allowed transition and n = 2 for a direct allowed transition. From the results, it could be seen that E-g strongly varied according to the equation used for the graphic representation. Differences in E-g up to 0.5 eV for the same semiconductor depending on the transition chosen were observed. Accurate E-g estimation in the four semiconductors studied was obtained by using the general equation alpha (h nu) a parts per thousand B (h nu - E-g)(n) (where alpha similar to F(R)) and indirect allowed transition.