Electronic structures of two types of TiO2 electrodes: inverse opal and nanoparticulate cases
Electronic structures of two types of TiO2 electrodes: inverse opal and nanoparticulate cases
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DOI：
10.1039/c5ra07092a
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发表时间：
2015-01-01
期刊：
影响因子：
3.9
通讯作者：
Shen, Qing
中科院分区：
文献类型：
--
作者：
Toyoda, Taro;Yindeesuk, Witoon;Shen, Qing
我们比较了反蛋白石(IO)和纳米颗粒(NP)-二氧化钛电极的电子结构。通过光学吸收、荧光和价带研究获得了电子结构细节，以澄清使用IO-Ti02电极敏化的太阳能电池具有更高光伏性能的本质。我们用光声(PA)和光致发光(PL)光谱分别表征了其光学吸收和荧光性质。用光电子产额(PY)谱表征了IO-和NP-TiO2电极的价带最大值(VBM)的位置。IO-TiO_2和NP-TiO_2的PA谱不同，反映了激子-声子相互作用和导带中态密度的不同。PL测量表明，IO-TiO2价带结构的曲率与NP-TiO2价带结构的曲率不同。光致发光测试还表明，IO-Ti02中的氧空位与NP-TiO2中的不同。此外，PY测量表明，IO-TiO2中的VBM位置高于NP-TiO2中的VBM，这表明与敏化太阳能电池中开路电压(V-oc)的增加有关。
We present a comparison between the electronic structures of inverse opal (IO) and nanoparticulate (NP)-TiO2 electrodes. The electronic structure details were obtained from optical absorption, fluorescence, and valence band studies in order to clarify the nature of the higher photovoltaic performance observed in sensitized solar cells using IO-TiO2 electrodes. We used photoacoustic (PA) and photoluminescence (PL) spectroscopy to characterize the optical absorption and fluorescence properties, respectively. Photoelectron yield (PY) spectroscopy was applied to characterize the position of the valence band maximum (VBM) of the IO- and NP-TiO2 electrodes. The PA spectrum for IO-TiO2 is different to that for NP-TiO2, indicating differences in the exciton-phonon interactions and the density of states in the conduction band. PL measurements showed that the curvature of the valence band structure of IO-TiO2 is different to that of NP-TiO2. Also, PL measurements showed that the oxygen vacancy in IO-TiO2 is different to that in NP-TiO2. Moreover, PY measurements showed VBM in IO-TiO2 to be at a higher position than that in NP-TiO2, suggesting a correlation with the increased open circuit voltage (V-oc) in sensitized solar cells.