%A Shuangying XU, Linhua HU, Jiang SHENG, Dongxing KOU, Huajun TIAN, Songyuan DAI %T Electron transportation and optical properties of micro-structure TiO2 films: applied in dye-sensitized solar cells %0 Journal Article %D 2011 %J Front. Optoelectron. %J Frontiers of Optoelectronics %@ 2095-2759 %R 10.1007/s12200-011-0202-5 %P 72-79 %V 4 %N 1 %U {https://journal.hep.com.cn/foe/EN/10.1007/s12200-011-0202-5 %8 2011-03-05 %X

Micro-structure of TiO2 films in dye-sensitized solar cells (DSSCs) can affect light absorption and electron transportation that impact on the characteristics of current-voltage (J-V). In this paper, films with different surface area, pore size and porosity were obtained by adding different ratio of ethyl cellulose (Ec-S) to pastes, and a photo-electric conversion efficiency (η) of 7.55% with a short-circuit current density (Jsc) of 16.81 mA·cm-2 was obtained when the ratio of Ec-S was 10∶5. BET results showed that film with this optimum ratio had the most suitable pore size and surface area for good properties of photovoltaic, which had a low reflectivity and high transmission rate, and the efficiency of light utilization was improved. Moreover, measurements by intensity-modulated photocurrent spectroscopy (IMPS) and intensity-modulated photovoltage spectroscopy (IMVS) implied that the electron transport time (τd) increased as the content of Ec-S increased, which was related to the larger surface area. Results of steady-state cyclic voltammetry indicated that diffusion-limited current density (Jlim) of I3- in TiO2 film increased with its porosity, which revealed that the transportation of redox mediators in the electrolyte was speeded up.