Publication

Photocapacitance of Nanocrystalline Oxide Semiconductor Films: Band-Edge Movement in Mesoporous TiO2 Electrodes during UV Illumination

Michael Graetzel
1996
Journal Articles

Abstract

Impedance measurements of meso-porous TiO2 electrodes in contact with aq. and nonaq. electrolytes have been performed in the dark and under UV illumination. In the dark the differential capacitance was found to be dominated by the back contact. Bandgap excitation of the TiO2 film turned on a capacitance assocd. with the meso-porous semiconductor layer. This is interpreted in terms of trapping of photogenerated holes in surface states leading to unpinning of the energy bands. The unpinning of the energy bands during UV illumination was confirmed by a dye-sensitization expt.

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https://infoscience.epfl.ch/entities/publication/b339e1ce-16f1-4219-98a7-901e5b672b05

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Michael Graetzel
1996
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/b339e1ce-16f1-4219-98a7-901e5b672b05

About this result

Related concepts (28)

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In solid-state physics and solid-state chemistry, a band gap, also called a bandgap or energy gap, is an energy range in a solid where no electronic states exist. In graphs of the electronic band structure of solids, the band gap refers to the energy difference (often expressed in electronvolts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. It is the energy required to promote an electron from the valence band to the conduction band.

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Photocapacitance of Nanocrystalline Oxide Semiconductor Films: Band-Edge Movement in Mesoporous TiO2 Electrodes during UV Illumination

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