Organometal hybrid trihalide perovskite solar cells (PSCs) have emerged a new class of optoelectronic devices for various applications. PSCs have demonstrated unprecedented progress in efficiency reaching certified power conversion efficiency up to 22.1% after only several years of active research. In this paper, we demonstrate inverted planar mixed halide perovskite solar cells where perovskite layers are built by two-step modified interdifussion and one-step methods. We demonstrate how PSC parameters change by doping electron transport layer (ETL). We used N,N-dimethyl-N-octadecyl(3-aminopropyl) trimethoxysilyl chloride (DMOAP) as dopant for ETL [6,6]-phenyl C61 butyric acid methyl ester (PCBM). The highest EQE and Voc values were obtained for cell prepared by one-step method with fast crystallization and doped ETL but higher fill factor (FF) and shunt resistance (Rshunt) values were obtained for cells prepared by two-step method with undoped ETL.