Schiaber, Ziani de Souza [UNESP]Calabrese, GabrieleKong, XiangTrampert, AchimJenichen, BerndDias da Silva, Jose Humberto [UNESP]Geelhaar, LutzBrandt, OliverFernandez-Garrido, Sergio2018-11-262018-11-262017-01-01Nano Letters. Washington: Amer Chemical Soc, v. 17, n. 1, p. 63-70, 2017.1530-6984http://hdl.handle.net/11449/159299We present a conceptually novel approach to achieve selective area epitaxy of GaN nanowires. The,approach is based on the fact that these nanostructures do not form in plasma-assisted molecular beam epitaxy on structurally and chemically uniform cation-polar substrates. By in situ depositing and nitridating Si on a Ga-polar GaN film, we locally reverse the polarity to induce the selective area epitaxy of N-polar GaN nanowires. We show that the nanowire number density can be controlled over several orders of magnitude by varying the amount of predeposited Si. Using this growth approach, we demonstrate the synthesis of single-crystalline and uncoalesced nanowires with diameters as small as 20 nm. The achievement of nanowire number densities low enough to prevent the shadowing of the nanowire sidewalls horn the impinging fluxes paves the way for the realization of homogeneous core-shell heterostructures without the need of using ex situ prepatterned substrates.63-70engSelective area growthmaskless selective area epitaxypolarity inversionsemiconductornanocolumnArtigo10.1021/acs.nanolett.6b03249WOS:000392036600010Acesso restrito