Recently, there has been a remarkable improvement in the efficiency of organic-inorganic perovskite solar cells (PSCs). However, the complexity of the fabrication process for these PSCs has increased due to the post-processing of the perovskite layer and the use of antisolvents, among others. In this investigation, a straightforward method for fabricating high-performance and CH3NH3+-free [CH(NH2)2PbI3]0.95[CsPbBr3]0.05 solar cells using fluorinated phosphoric acid passivating additives in combination with mixed solvents was presented. This study required neither post-treatment nor anti-solvent for solar cell fabrication. Fluorinated phosphoric acid was introduced into the perovskite layer, which then self-organized on the perovskite surface and exhibited a passivating effect. Planar PSCs fabricated at reduced temperatures without fluorinated phosphoric acid exhibited power conversion efficiencies (PCEs) of 19.9 % and 17.3 % during reverse and forward scanning, respectively. Conversely, PSCs fabricated with fluorinated phosphoric acid as an additive exhibited a remarkable PCE of 20.5 % without hysteresis and a stabilized power output of 20.4 %. This study will facilitate the fabrication of high-efficient PSCs in future research efforts, thereby promoting the advancement of these devices.