Impact of the architecture of dye sensitized solar cell-powered electrochromic devices on their photovoltaic performance and the ability to color change

The functional layers arrangement in a dye sensitized solar cell electrochromic device (DSSC-EC) on the energy conversion efficiency and on the ability to change the color is studied. The highest power conversion efficiency of ca. 7% and good color change in closed circuit conditions was observed with electrochromic WO3 deposited on the counter-electrode of the DSSC. When WO3 layer was applied over the photoanode, the DSSC-EC displayed less power conversion efficiency - 3.4%, but a more intense color change was observed under illumination and opened external circuit. Response of the photocurrent vs. applied potential, incident photon-to-current conversion efficiency and optical behavior of the DSSC-EC were assessed and discussed considering optical properties of the components of the device and their energy bands alignment. Smart window and self-powered proof-of-concept pixelated device operating on DSSC-EC are presented.