title: Nanometer-scale dielectric imaging of semiconductor nanoparticles: size-dependent dipolar coupling and contrast reversal.
abstract: Scattering-type apertureless near-field microscopy (ANSOM) provides high-resolution dielectric maps of indium gallium nitride (InGaN) semiconductor nanoparticles at visible (633 nm) wavelengths. A specific size-dependent contrast reversal is observed in the ANSOM images of InGaN nanoparticles grown on a layer of gallium nitride (GaN). Model calculations demonstrate that the observed contrast reversal is the result of the competition between the tip-particle versus tip-substrate dipolar coupling.
authors.affiliation: Department of Chemistry and Center for Electro- and Photo-Responsive Molecules, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-701, Republic of Korea.
authors.forename: Zee Hwan
authors.initials: ZH
authors.lastname: Kim
authors.forename: Sung-Hyun
authors.initials: SH
authors.lastname: Ahn
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Leone
mesh_terms: D003460:Crystallization / Q000379:methods*; D017097:Electric Impedance; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing / Q000379:methods; D018625:Microscopy, Atomic Force / Q000379:methods*; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012666:Semiconductors; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances