Simultaneous Optical and Electrical Characterization of GaN Nanowire Arrays by Means of Vis-IR Spectroscopic Ellipsometry

• We report an original and straightforward method for both optical and electrical characterization of vertical GaN nanowire arrays epitaxially grown on silicon through visible-infrared spectroscopic ellipsometry methods. For the initial purpose of adding new inputs to the ellipsometry model, focused ion-beam tomography experiments were conducted to extract porosity/depth profiles of these systems. To reproduce the optical free-carrier behavior in the infrared, the ellipsometric data acquired were fitted to an anisotropic Bruggeman model including Tauc-Lorentz and Drude oscillators, which enabled the determination of carrier density and in-grain mobility. The nice agreement of these results with those obtained by combining Hall effect measurements, X-ray diffraction, and transmission electron microscopy studies supported the validity of the proposed method, opening new horizons in the characterization of nanowire-based semiconducting layers.

Subject headings

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Publication and Content Type

art (subject category)

ref (subject category)