From Dots to Stripes to Sheets: Shape Control of Lead Sulfide Nanostructures

Controlling anisotropy in nanostructures is a challenging but rewarding task because confinement in one or more dimensions influences the physical and chemical properties of the items decisively. In particular, semiconducting nanostructures can be tailored to gain optimized properties to work as transistors or absorber material in solar cells. We demonstrate that the shape of colloidal lead sulfide nanostructures can be tuned from spheres to stripes to sheets by means of the precursor concentrations, the concentration of a chloroalkane coligand and the synthesis temperature. All final structures still possess at least one dimension in confinement. The structures cover all dimensionalities from 0D to 3D. Additionally, the effect of temperature on the shape and thickness of PbS nanosheets is shown and electrical transport measurements complement the findings.