Highly transparent photoelectrochromic device based on carbon quantum dots sensitized photoanode

The combination of dye or quantum dots sensitized solar cell and electrochromic device has led to the realization of the photoelectrochromic device (PECD). In this study, a PECD consisted of carbon quantum dots (CQDs) sensitized photoanode, poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDOT-Me-2) electrochromic film, Br-/Br-3(-) with Li+ as electrolyte was fabricated, and it shows advantages of highly transparency for bleached state when compared with conventional photoelectrochromic device. As a PECD, it exhibits a reversible optical modulation under constant illumination (100 mW cm(-2)) by simply altering its circuit states between on and off. A high optical window of 54.6% with coloration time of 4.9 s, and bleaching time of 5.2 s was achieved at 580 nm. Additionally, stable switching for transmittance modulation after 400 cycles demonstrates its good cycle durability, exhibiting great potential in developing energy-saving applications.