Methylammonium lead halide perovskites used in photovoltaic devices are generally deposited from high boiling point solvents with low volatility such as N,N-dimethylformamide. The slow drying causes the formation of relatively large perovskite crystallites that enhance surface roughness and lead to pin holes between the crystallites. We show that the use of 2-methoxyethanol, which is a more volatile solvent, results in smaller crystals that still span the entire layer thickness. This improves the surface coverage of perovskite films, reduces the leakage current and increases the open-circuit voltage and fill factor of solar cells. P-I-N configuration solar cells, processed under ambient conditions from a triple anion (iodide, chloride, and acetate) lead precursor salt, provide an increase in the power conversion efficiency from 14.1% to 15.3% when N,N-dimethylformamide is replaced by 2-methoxyethanol as the solvent.