To increase more than 10% in efficiency of perovskite solar cells by using nanoholes SnO 2

The perovskite solar cells have been intensively investigated these years due to their premium electrical and optical properties as well as huge potential for application. In order to further increase the power conversion efficiency (PCE) of the thin film perovskite solar cells, light management should be taken into consideration. Herein, we apply a lithography method to transfer randomly distributed polystyrene (PS) nanospheres into the electron transporting SnO 2 layer, by means of which, a nanoholes structure is formed. Finally, we get a nanostructured perovskite layer under low temperature (less than 150 °C). The depth of SnO 2 nanoholes is around 60 nm when the device is fabricated with 300-nm PS, and 150 nm in depth when 500-nm PS is used. The device gains PCE of 17.97%, which is 12.3% higher than that with planar electron-transporting SnO 2 layer and 300-nm CH 3 NH 3 PbI 3 layer. Our findings provide an applicable method to improve the light absorption, which can not only make the absorbing layer of lead-based perovskite solar cells thinner to help decrease the content of lead, but also increase the PCE of non-lead perovskite devices. Graphic abstract