Wavefunction Mapping of Immobilized InP Semiconductor Nanocrystals

Individual wavefunctions (WF) in colloidal nanocrystals (NC) were directly mapped by acquiring bias-dependent and spatially resolved differential tunneling conductance (dI/dV) maps and the symmetry of the squared WFs corresponding to the different states resolved in the spectral density was determined. InP nanoparticles were prepared by the dehalosilylation reaction between indium chloride and tris(trimethylsilyl)phosphine in mixtures of trioctylphosphine and trioctylphosphine oxide. A low-temperature scanning tunneling microscopy (STM) image of the dithiol layer show that individual molecules are distinguishable on the thiolated Au surface, which exhibits small molecularly ordered domains together with some vacancy islands. Results of the normalized derivative [(dI/dV)/(I/V)] spectra in the shell-filling regime show that the intensities of the low-energy peaks decrease while the others increase in weight.