title: Crystallographic Characterization of II-VI Semiconducting Nanostructures via Optical Second Harmonic Generation.
abstract: We demonstrate the utility of optical second harmonic generation (SHG) polarimetry to perform structural characterization of noncentrosymmetric, single-crystalline II-VI semiconducting nanowires, nanobelts, and nanoflakes. By analyzing anisotropic SHG polarimetric patterns, we distinguish between wurtzite and zincblende II-VI semiconducting crystal structures and determine their growth orientation. The crystallography of these nanostructures was then confirmed via transmission electron microscopy measurements performed on the same system. In addition, we show that some intrinsic material properties such as nonlinear coefficients and geometry-dependent optical in-coupling coefficients can also be determined from the SHG experiments in WZ nanobelts. The ability to perform SHG-based structural characterization and crystallographic study of II-VI semiconducting single-crystalline nanomaterials will be useful to correlate structure-property relationships of nanodevices on which transmission electron microscopy measurements cannot be typically performed.
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Ming-Liang
authors.initials: ML
authors.lastname: Ren
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Rahul
authors.initials: R
authors.lastname: Agarwal
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Ritesh
authors.initials: R
authors.lastname: Agarwal
keywords: Second harmonic generation; crystal structure; nanowires; nonlinear optics; photoluminescence; semiconductor; transmission electron microscope