American Chemical Society, ACS Applied Materials and Interfaces, 4(6), p. 2415-2422, 2014
DOI: 10.1021/am404800m
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A photovoltachromic window can potentially act as a smart glass skin which generates electric energy as a common dye-sensitized solar cell and, at the same time, controls the incoming energy flux by reacting to even small modifications in the solar radiation intensity. We here report the successful implementation of a novel architecture of a photovoltachromic cell based on an engineered bi-functional counter electrode consisting of two physically separated platinum and tungsten oxide regions, which are arranged to form complementary comb-like patterns. Solar light is partially harvested by a dye-sensitized photoelectrode made on the front glass of the cell which fully overlaps a bi-functional counter electrode made on the back glass. When the cell is illuminated, the photovoltage drives electrons into the electrochromic stripes through the photoelectrochromic circuit and promotes the Li+ diffusion towards the WO3 film, which thus turns in its colored state: a photo-coloration efficiency of 17 cm2*min-1*W-1 at a wavelength of 650 nm under 1.0 sun was reported along with fast (coloration time < 2 sec and bleaching time < 5 sec) response. A fairly efficient photovoltaic functionality was also retained due to the co-presence of the independently switchable micro-patterned Platinum electrode.