Photoassisted electrical transport in porous TiO2

2020-01-06 10:06:46

potential TiO2 bias light porous

责任者: Kytin, V.;Petrov, A.;Timoshenko, V.Yu.;Parkhutik, V.;Kashkarov, P.K.;Wiedmann, J.;Koch, F.;Dittrich, T. 单位: Dept. of Phys., Technische Univ. Munchen, Garching, Germany 来源出处: Physica Status Solidi A(Phys. Status Solidi A (Germany)),2003/05/,197(2):487-91 摘要: The photoassisted electrical transport is investigated in porous TiO2 (anatase) layers by impedance spectroscopy (IS) and time-of-flight (TOF) at different temperatures and pressures of oxygen. The experiments were carried out under the conditions of zero bias potential (no electron injection at the contacts takes place) and of relatively high bias potential when electrons are injected from the contact into the porous TiO2 layer. Illumination with photons having energies below the band gap leads to a strong increase of the conductivity while the conductivity is practically unchanged for illumination with ultra violet light independent of the applied bias potential. Besides the light induced excess carrier generation. TOF measurements show an increase of the drift mobility under illumination with blue light. The results were explained by the lowering of the barriers between sintered TiO2 nanocrystals due to separation of photoexcited charge carriers 关键词: carrier mobility;charge injection;nanostructured materials;photoconductivity;photoexcitation;porous semiconductors;sintering;time of flight spectra;titanium compounds;photoassisted electrical transport;porous TiO2;anatase;impedance spectroscopy;time-of-flight;TOF;oxygen pressure;zero bias potential;electron injection;photons illumination;band gap;conductivity;ultraviolet light;carrier generation;drift mobility;blue light;sintered TiO2 nanocrystals;photoexcited charge carriers;TiO2