Agradecimentos: We acknowledge the Brazilian Nanotechnology Laboratory (LNNano/CNPEM) for granting access to their electron microscopy facilities, and the Brazilian agency CAPES. B. C. da Silva acknowledges FAPESP for his scholarship (grant 15/24271-9). We also thank M. M. Tanabe for technical...

Agradecimentos: We acknowledge the Brazilian Nanotechnology Laboratory (LNNano/CNPEM) for granting access to their electron microscopy facilities, and the Brazilian agency CAPES. B. C. da Silva acknowledges FAPESP for his scholarship (grant 15/24271-9). We also thank M. M. Tanabe for technical support with the optical setup. This work was financially supported by the Brazilian agencies CNPq (grants 305769/2015-4, 432882/2018-9, 479486/2012-3 and 441799/2016-7) and FAPESP (grants 15/16611-4, 12/11382-9 and 16/16365-6)

Abstract: Definitive evidence for the direct band gap predicted for Wurtzite Gallium Phosphide (WZ GaP) nanowires has remained elusive due to the lack of strong band-to-band luminescence in these materials. In order to circumvent this problem, we successfully obtained large volume WZ GaP structures...

Abstract: Definitive evidence for the direct band gap predicted for Wurtzite Gallium Phosphide (WZ GaP) nanowires has remained elusive due to the lack of strong band-to-band luminescence in these materials. In order to circumvent this problem, we successfully obtained large volume WZ GaP structures grown by nanoparticle-crawling assisted Vapor-Liquid-Solid method. With these structures, we were able to observe bound exciton recombination at 2.14 eV with FHWM of approximately 1 meV. In addition, we have measured the optical absorption edges using photoluminescence excitation spectroscopy. Our results show a 10 K band gap at 2.19 eV and indicate a weak oscillator strength for the lowest energy band-to-band absorption edge, which is a characteristic feature of a pseudo-direct band gap semiconductor. Furthermore, the valence band splitting energies are estimated as 110 meV and 30 meV for the three highest bands. Electronic band structure calculations using the HSE06 hybrid density functional agree qualitatively with the valence band splitting energies

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

12/11382-9; 15/16611-4; 15/24271-9; 16/16365-6

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

479486/2012-3; 305769/2015-4; 441799/2016-7; 432882/2018-9

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