title: Self-assembled GaN nanowires on diamond.
abstract: We demonstrate the nucleation of self-assembled, epitaxial GaN nanowires (NWs) on (111) single-crystalline diamond without using a catalyst or buffer layer. The NWs show an excellent crystalline quality of the wurtzite crystal structure with m-plane faceting, a low defect density, and axial growth along the c-axis with N-face polarity, as shown by aberration corrected annular bright-field scanning transmission electron microscopy. X-ray diffraction confirms single domain growth with an in-plane epitaxial relationship of (10 ̅10)(GaN) [parallel] (01 ̅1)(Diamond) as well as some biaxial tensile strain induced by thermal expansion mismatch. In photoluminescence, a strong and sharp excitonic emission reveals excellent optical properties superior to state-of-the-art GaN NWs on silicon substrates. In combination with the high-quality diamond/NW interface, confirmed by high-resolution transmission electron microscopy measurements, these results underline the potential of p-type diamond/n-type nitride heterojunctions for efficient UV optoelectronic devices.
authors.affiliation: Walter Schottky Institut, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany. Fabian.Schuster@wsi.tum.de
authors.forename: Fabian
authors.initials: F
authors.lastname: Schuster
authors.forename: Florian
authors.initials: F
authors.lastname: Furtmayr
authors.forename: Reza
authors.initials: R
authors.lastname: Zamani
authors.forename: Cesar
authors.initials: C
authors.lastname: Magén
authors.forename: Joan R
authors.initials: JR
authors.lastname: Morante
authors.forename: Jordi
authors.initials: J
authors.lastname: Arbiol
authors.forename: Jose A
authors.initials: JA
authors.lastname: Garrido
authors.forename: Martin
authors.initials: M
authors.lastname: Stutzmann