Fabrication and characterization of CH <sub>3</sub> NH <sub>3</sub> PbI <sub>3</sub> solar cells with added guanidinium and inserted with decaphenylpentasilane
Iori Ono, Takeo Oku, Atsushi Suzuki, Yugo Asakawa, Shuhei Terada, Masanobu Okita, Sakiko Fukunishi, Tomoharu Tachikawa
Abstract
Abstract In this work we investigated the effects of the addition of guanidinium [C(NH 2 ) 3 ; GA] on CH 3 NH 3 PbI 3 perovskite solar cells fabricated at a high temperature of 190°C in atmospheric air. The addition of GA iodide and the insertion of decaphenylpentasilane between the perovskite and hole transport layer improved the external quantum efficiency and short-circuit current density, and the conversion efficiencies were stable after 1 month. X-ray diffraction showed that the lattice constant of the perovskite crystals was increased by the addition of GA, and addition of GA also improved the surface morphology. First-principles calculations on the density of states and band structures showed reduction of the total energy by the addition of GA and the effectiveness of the nitrogen atoms in GA.