New ways to synthesize lead sulfide nanosheets - substituted alkanes   direct the growth of 2D nanostructures
  Two-dimensional colloidal nanosheets represent very attractive optoelectronic materials. They combine good lateral conductivity with solution-processability and geometry-tunable electronic properties. In case of PbS nanosheets, so far the synthesis was driven by the addition of chloroalkanes as coligands. Here, we demonstrate how to synthesize two-dimensional lead sulfide nanostructures using other halogen alkanes and primary amines. Further, we show that at a reaction temperature of 170C a coligand is not even necessary, and the only ligand, oleic acid, controls the anisotropic growth of the two-dimensional structures and using thiourea as sulfide source, nanosheets with lateral dimensions of over 10 microns are possible. 
Thomas Bielewicz, Eugen Klein, Christian Klinke
cond-mat.mtrl-sci