Growth of large CH3NH3PbX3 (X=I, Br) single crystals in solution

We present the results on the successful growth of CH3NH3PbX3 (X=I, Br) single crystals sized up to centimeters using hydrohalic acid solution method. Large crystals with perfect morphology were obtained by a very slow cooling rare of 0.1-0.2 degrees C/h. The lattice parameters of tetragonal CH(3)NH(3)Pbl(3) and cubic CH3NH3PbBr3 were estimated using the Rietveld refinement method. Study of crystal nucleus, habits and dimensions indicates that these are strongly dependent on the supercooling of solution during crystal growth, in which the (001)/(010) for CH(3)NH(3)Pbl(3) and {100} for CH3NH3PbBr3 always exhibit the largest faces on the as-grown crystals. A structural phase transition of tetragonal/cubic and cubic/tetragonal for the CH(3)NH(3)Pbl(3) single crystals was observed to occur at 62 and 60 degrees C during the heating and cooling process, respectively. The nonlinear relationship of temperature-dependent solubility for CH(3)NH(3)Pbl(3) in hydrohalic acid was also determined. (C) 2015 Elsevier B.V. All rights reserved.