title: Fast-switching photovoltachromic cells with tunable transmittance.
abstract: In this study, we demonstrate a photovoltachromic cell (PVCC) which is a solar cell and able to take solar energy to stimulate chromic behavior with the characteristic of tunable transmittance. The cell is composed of a patterned WO(3)/Pt electrochromic electrode and a dye-sensitized TiO(2) nanoparticle photoanode. Compared to reported photoelectrochromic cells (PECC) with nonpatterned WO(3) electrochromic electrodes, PVCC achieves a much faster bleaching time of only 60 s by blocking the light at short circuit. When PVCC is bleached under illumination at open circuit, an exceedingly short bleaching time of 4 s is achieved. Furthermore, PVCC has photovoltaic characteristics comparable to those of dye-sensitized solar cells (with Pt as the counter-electrode). In contrast to conventional photochromic devices, the transmittance of PVCC under a constant illumination can be adjusted by the resistance of a load in series with the cell. These characteristics are a result of the patterned WO(3)/Pt electrode, which provides effective charge transfer pathways to facilitate the charging/discharging of Li ions and electrons via the photovoltaic potential and the Pt-electrolyte catalytic route, respectively.
authors: Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan. wujj@mail.ncku.edu.tw
authors: Jih-Jen
authors: JJ
authors: Wu
authors: Min-Da
authors: MD
authors: Hsieh
authors: Wen-Pin
authors: WP
authors: Liao
authors: Wei-Ting
authors: WT
authors: Wu
authors: Jen-Sue
authors: JS
authors: Chen