Temperature-assisted controlling morphology and charge transport property for highly efficient perovskite solar cells

Reaction temperature as a key parameter has been introduced to manipulate the film deposition of the CH3NH3PbI3 absorber fabricated by the two-step solution deposition method. It is found that conversion time of dense CH3NH3PbI3 layer can be significantly reduced by raising reaction temperature. CH3NH3PbI3 crystal grain sizes increase with reaction temperature increasing, resulting in rougher surface. CH3NH3PbI3 films deposited at higher temperatures exhibit better charge transport ability, larger built-in heterojunction field and weaker charge recombination, leading to enhanced solar cell performance. By optimizing reaction temperatures, as high as 17.40% and 14.02% of power conversion efficiencies of the mesoscopic and planar perovskite solar cells have been achieved, respectively. (C) 2015 Elsevier Ltd. All rights reserved.