Effects of guanidinium iodide surface treatment on CH3NH3PbI3 perovskite solar cells with added decaphenylcyclopentasilane
Keisuke Kuroyanagi, Takeo Oku, Iori Ono, Riku Okumura, Ayu Enomoto, Atsushi Suzuki, Sakiko Fukunishi, Tomoharu Tachikawa, Tomoya Hasegawa
Abstract
The effects of guanidinium iodide surface treatment (GST) on CH3NH3PbI3 perovskite solar cells with decaphenylcyclopentasilane (DPPS) were investigated. GST decreases the carrier trap density and improves the photovoltaic characteristics. The X-ray diffraction results showed that the lattice constants of the perovskite crystals were increased by the insertion of GST and guanidinium into the methylammonium defects. The thermal stability of the unlaminated devices was tested in the air at 85°C. The device prepared using GST exhibited the highest conversion efficiency. First-principles calculations supported these experimental results.