@InProceedings{MoellerOCSIMMLGC:2015:AuZiDe,
               author = "Moeller, Michael and Oliveira, Douglas Soares and Cotta, Monica A. 
                         and Sahoo, Prasana K. and Iikawa, Fernando and Motisuke, Paulo and 
                         Molina, Alejandro and Lima, Maur{\'{\i}}cio M. de and 
                         Garcia-Cristobal, Alberto and Cantarero, Andres",
          affiliation = "{Universidade Estadual de Campinas (UNICAMP)} and {Universidade 
                         Estadual de Campinas (UNICAMP)} and {Universidade Estadual de 
                         Campinas (UNICAMP)} and {Universidade Estadual de Campinas 
                         (UNICAMP)} and {Universidade Estadual de Campinas (UNICAMP)} and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)} and {University 
                         of Luxembourg} and {Universitat de Valencia} and {Universitat de 
                         Valencia} and {Universitat de Valencia}",
                title = "Au-nanoparticle zize dependent fermi energy in catalyst growth 
                         InAs nanowires",
                 year = "2015",
         organization = "Materials Research Society: Fall Meeting",
             abstract = "Semiconductor nanowires (NWs) are very promising in future 
                         applications and already have been included in several 
                         optoelectronic devices such as lasers, solar cells, LEDs and 
                         sensors. A remarkable property of InAs NWs, as well as other 
                         arsenide and phosphide III-V semiconductor compounds, is the 
                         growth of the hexagonal wurtzite (WZ) crystal phase, while the 
                         most stable phase in bulk is the zincblende (ZB) one. Concerning 
                         the optical properties, the WZ phase presents several absorption 
                         peaks as compared to the cubic phase counterpart, due to the 
                         valence band splitting as well as the folding of the conduction 
                         band due to the Brillouin zone reduction. In this context, even 
                         though the InAs WZ structure has been extensively investigated, 
                         the results of its optical properties remain a matter of 
                         controversy, as in the case of the bandgap energy due to the 
                         strong effects of the surface on the optical spectra. In this 
                         contribution, InAs and InAs/InP core/shell nanowires grown by 
                         vapor-liquid-solid method are investigated by photoluminescence 
                         spectroscopy. Two set of samples are grown using different 
                         Au-nanoparticle sizes (5 and 20 nm), in Chemical beam epitaxy 
                         system. One of them is capped with InP shell and other one is pure 
                         InAs. All NWs are predominantly in wurtzite phase. We observe that 
                         capping InAs nanowires with an InP shell enhances the optical 
                         emission without affecting the Fermi energy which is above the 
                         conduction band edge. In contrast, the Fermi energy is reduced by 
                         ~20 meV when the Au-nanoparticle size increases from 5 to 20 nm. 
                         This is attributed to the differences in residual carbon 
                         incorporation into the catalyst-growth axial and the 
                         non-catalyst-growth radial layers. These results are corroborated 
                         using a self-consistent method to calculate the Fermi energy 
                         variation when the diameter of Au-nanoparticle increases. This 
                         effect can be useful to control the optical emission for device 
                         applications.",
  conference-location = "Boston, MA",
      conference-year = "29 Nov. - 04 Dec.",
        urlaccessdate = "23 maio 2024"
}