Size effect of POMs promoting electron transfer to improve the performance of dye-sensitized solar cells.

LI Xiaohong; ZHANG Yuteng; YU Haihui; TIAN Xiaoli; ZHANG Haifeng; CHEN Weilin

In recent years, dye-sensitized solar cells (DSSCs) have attracted much attention due to their ability to efficiently convert light energy into electricity. The enhancement of electron transfer efficiency and the suppression of interfacial charge recombination are essential for the development of DSSCs. Polyoxometalates (POMs) have already been confirmed to act as effective electron-transfer mediators for accepting and delivering electrons remaining the integrated structure. Due to size effect, nano-sized POMs with more active sites, exposed more surface area, and changed electronic structure enhance the inherent activity. Further, the nano-sized POMs aiming on titanium dioxide (TiO2) shortens the electron transport distance, accelerate the electron transfer, and effectively suppresses the electron-hole recombination, thus improving the electron utilization and enhancing the power conversion efficiency (PCE) of the DSSCs. Taking PMo12 as an example, we prepared PMo12 to a nanometer size of about 50 nm by freeze-drying technology and further combined with TiO2 as photoanodes. To our satisfying surprise, a significant improvement of PCE in DSSCs is obtained as high as 8.12%, which is 22.3% and 47.3% higher than the original PMo12/TiO2 composite material and TiO2 alone, respectively.

DYE-sensitized solar cells; ELECTRON transport; CHARGE exchange; ELECTRON-hole recombination; ELECTRONIC structure

Journal of Molecular Science, 2024, Vol 40, Issue 5, p441

1000-9035

Academic Journal

10.13563/j.cnki.jmolsci.2024.05.108