Effect of Point Defects and Impurities on the Electronic Transport of Au Tipped Ultranarrow PbS Nanorods

Electronic transport through single nanowire/nanorod directly probes the fundamental limits of semiconductor device miniaturization. Point defects or impurity centers form easily during the growth of nanorods/nanowires which may strongly affect the electronic transport efficiencies. Existing models of electronic transport are often unable to determine the role of defects and impurities at the nanoscale because there are significant differences between nanostructures and bulk materials arising from unique geometries and confinement. The effect of defect and impurities on the conductance of a model ultranarrow PbS rod was modeled using density functional theory. It was observed that the introduction of defects and Au impurities modified the orbital energies of PbS nanorods and reduced the conductance compared to the defect-free rod. The conductance for the nanorods with defects and impurities were limited by the number of available conduction channels required for efficient electronic conduction.