title: Spectroscopic characterizations of individual single-crystalline GaN nanowires in visible/ultra-violet regime.
abstract: Spectroscopic investigations of individual single-crystalline GaN nanowires with a lateral dimensions of approximately 30-90nm were performed using the spatially resolved technique of electron energy-loss spectroscopy in conjunction with scanning transmission electron microscope showing a 2-A electron probe. Positioning the electron probe upon transmission impact and at aloof setup with respect to the nanomaterials, we explored two types of surface modes intrinsic to GaN, surface exciton polaritons at approximately 8.3eV (approximately 150nm) and surface guided modes at 3.88eV (approximately 320nm), which are in visible/ultra-violet spectral regime above GaN bandgap of approximately 3.3eV (approximately 375nm) and difficult to access by conventional optical spectroscopies. The explorations of these electromagnetic resonances might expand the current technical interests in GaN nanomaterials from the visible/UV range below approximately 3.5eV to the spectral regime further beyond.
authors.affiliation: Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan.
authors.forename: Chien-Ting
authors.initials: CT
authors.lastname: Wu
authors.forename: Ming-Wen
authors.initials: MW
authors.lastname: Chu
authors.forename: Li-Chyong
authors.initials: LC
authors.lastname: Chen
authors.forename: Kuei-Hsien
authors.initials: KH
authors.lastname: Chen
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Chen
authors.forename: Cheng Hsuan
authors.initials: CH
authors.lastname: Chen