"This work reports the fabrication of perovskite films (CH3NH3PbI3) by one-step spin-coating method. The influence of several factors such as the atmosphere for deposition and annealing treatment, the use of co-solvent dimethylsulfoxide, and chlorobenzene washing on the morphology and crystalline structure was analyzed. Solar cells with the architecture ITO/PEDOT:PSS/Perovskita/PC71BM/FM were fabricated with such perovskite films. The devices presented an average power conversion efficiency (PCE) of 5.8 %, with Jsc = 14.8 mA/cm2, Voc = 846 mV, and FF= 0.46 with a photoactive area of 0.06 cm2. When the films were dried at high vacuum the device exhibited a PCE of 12.7 %, with Jsc = 21.9 mA/cm2, Voc = 860 mV, and FF= 0.68."