As it currently remains challenging to obtain precise control over the formation of the thin 2D layer used in 2D/3D heterojunction perovskite solar cells, researchers from China's Jinan University set out to design a method for the precise preparation of 2D/3D perovskite heterojunctions.
Using their new method, the team constructed two different 2D/3D heterojunctions using a vapor-solution mixed deposition method and compared them with heterojunctions formed via conventional solution methods, achieving a PCE of the device from 20.67 % to 22.68%. The new strategy could be a useful way to optimize perovskite films and advance the fabrication of high-efficiency perovskite solar cells.
In this study, a thin PbI2 layer was vapor-deposited on a 3D perovskite layer and transformed into 2D by spin-coating with a PEABr solution. This method, compared to directly converting the surface layer into 2D, reportedly resulted in enhanced uniformity, improved optical absorption, and fewer defects.
Consequently, both open-circuit voltage (Voc) and short-circuit current density (Jsc) were improved, leading to an increase in power conversion efficiency (PCE) from 20.67 % to 22.68 % (0.1 cm2), demonstrating excellent stability and repeatability.
