Double-layered TiO₂ photoelectrode with particulate structure prepared by one-step soaking method

Nanostructured TiO₂ films with double-layered structure are prepared by a facile one-step soaking method. We have investigated the morphology of nanostructured TiO₂ films by the reaction time of the soaking method, which has an effect on the thickness and layered structure of the TiO₂ films. The TiO₂ films prepared by this method have a unique double-layered structure, which is composed of a dense TiO₂ bottom layer and TiO₂ particulates on the bottom layer. By manipulating the reaction time of the soaking method, control of TiO₂ particulate formation on the surface of the dense TiO₂ bottom layer is possible. The double-layered structure of nanostructured TiO₂ films is effective for achieving sufficient adsorption of Sb₂S₃ sensitizer and light scattering effect of photoelectrodes for inorganic sensitized solar cells, which induces the enhancement of short circuit current of solar cell devices. Our solar cell device, using a doublelayered TiO₂ film with particulate structure as a photoelectrode, exhibited J_SC, V_OC, FF, and η values of 12.94 mA/cm², 498 mV, 57.0%, and 3.67%, respectively.