title: Bandgap Energy of Wurtzite InAs Nanowires.
abstract: InAs nanowires (NWs) have been grown on semi-insulating InAs (111)B substrates by metal-organic chemical vapor deposition catalyzed by 50, 100, and 150 nm-sized Au particles. The pure wurtzite (WZ) phase of these NWs has been attested by high-resolution transmission electron microscopy and selected area diffraction pattern measurements. Low temperature photoluminescence measurements have provided unambiguous and robust evidence of a well resolved, isolated peak at 0.477 eV, namely 59 meV higher than the band gap of ZB InAs. The WZ nature of this energy band has been demonstrated by high values of the polarization degree, measured in ensembles of NWs both as-grown and mechanically transferred onto Si and GaAs substrates, in agreement with the polarization selection rules for WZ crystals. The value of 0.477 eV found here for the bandgap energy of WZ InAs agrees well with theoretical calculations.
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 5, 00185 Roma, Italy.
authors.forename: Michele B
authors.initials: MB
authors.lastname: Rota
authors.affiliation: Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia.
authors.forename: Amira S
authors.initials: AS
authors.lastname: Ameruddin
authors.affiliation: Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia.
authors.forename: H Aruni
authors.initials: HA
authors.lastname: Fonseka
authors.affiliation: Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Dipartimento di Chimica, Sapienza Università di Roma , Piazzale A. Moro 5, 00185 Roma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mura
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 5, 00185 Roma, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Polimeni
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 5, 00185 Roma, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Miriametro
authors.affiliation: Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia.
authors.forename: H Hoe
authors.initials: HH
authors.lastname: Tan
authors.affiliation: Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia.
authors.forename: Chennupati
authors.initials: C
authors.lastname: Jagadish
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 5, 00185 Roma, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Capizzi
keywords: Wurtzite InAs nanowires; bandgap energy; polarization degree; steady-state photoluminescence