Effect of Polyethylene Glycol as Additive for Fully Screen-Printable Perovskite Solar Cells

Abstract

One of the efficient strategies for improving the performance of perovskite solar cells (PSCs) is to reduce the interfacial recombination loss, as well as to control the crystalline growth of perovskite by using additives. In fully screen-printable␣hole transport material-free PSCs with carbon electrode, the perovskite penetrates into the mesoporous structure of three layers (TiO2, ZrO2, and carbon), thus it is suggested that improving the perovskite crystalline growth will be very important to decrease the charge recombination and improve the transport of electric charge carriers. In this work, we introduced polyethylene glycol (PEG) as an additive into the perovskite precursor solution, which effectively improved the photovoltaic performance of the device. We found that PEG addition could effectively increase the perovskite crystal size and thus decrease the interfacial recombination loss and improve the light absorption by the perovskite film. When PEG was added, the performance of the solar cell increased from 11.07% to 14.71%, while the long-term stability of the device also improved.