Surfactant enhanced surface coverage of CH3NH3PbI3-xClx perovskite for highly efficient mesoscopic solar cells

Controlling the morphology of perovskite absorbers is important for achieving high performance devices. Polymer poly-(vinylpyrrolidone) (PVP) is applied as a surfactant to enhance the surface coverage of perovskite. The introduction of this polymer results in the production of perovskite films with smooth surfaces and uniform crystal domains. Sufficient surface coverage not only reduces the amount of light passed straight through the cell without absorption, but also reduces charge recombination at the interfaces. The cell power conversion efficiency (PCE) is enhanced from 4.51% to 8.74% under the optimum PVP doping ratio of 3.3 wt%. (C) 2014 Elsevier B.V. All rights reserved.