CH3NH3PbI3 converted from reactive magnetron sputtered PbO for large area perovskite solar cells

- DC reactive magnetron sputtering is introduced to fabricate the perovskite films.
- The sputtered PbO is used as precursor and directly converted to CH3NH3PbI.
- The as-prepared solar cells with an active area of 1.07 cm2 achieve a PCE of 10.7%.
- Our approach is competent for the fabrication of large area perovskite solar cells.

Adopting DC reactive magnetron sputtering technique, PbO film was fabricated on FTO-glass substrate coated with a nanocrystalline rutile titania (NRT) by using a pure metallic lead target in an Ar/O2 mixture. Then the as-prepared PbO film was converted to CH3NH3PbI3 through the sequential reactions occurred in isopropanol solution of CH3NH3I. The as-prepared perovskite film exhibits a surface morphology of high uniformity and good coverage over a large scale; the crystal grains reach the size of up to 600 nm, which is beneficial for enhancing light absorption and decreasing grain boundary. The solar cells with a structure of FTO/NRT/CH3NH3PbI3/Spiro-MeOTAD/Au were fabricated, where NRT was employed as the contact layer of the photovoltaic devices. Our champion cells with active area of 0.09 cm2 and 1.07 cm2 achieve the highest power conversion efficiency of 14.1% and 10.7%, respectively, under the standard AM 1.5 conditions. The present approach is competent for the fabrication of large area perovskite solar cells with the advantages of easy control, cost-saving, and less use of toxic reagents, and thus with potential applications.