Facilities
Synthesis and Nano Fabrication

MBE

General informations

Location
MM Building, Trieste, Italy
Main techniques and methods
molecular beam epitaxy (MBE), X-ray photoemission spectroscopy (XPS)
Key instumentation
- two MBE growth chambers
- one metallization chamber
- one analysis chamber for XPS

The MBE lab is a facility for epitaxial growth of layers and nanostructures based on III-V, II-VI and V-VI compounds

Technical description

The MBE group runs a multi-chamber ultra-high vacuum system including:

• two twins Riber 32P molecular beam epitaxy growth chambers for III-V (AI, Ga, In)As andII-V-VI (Zn, Cd,Mn)(Bi, Sb)(Se, Te) semiconductor compounds;

• an analysis chamber for x-ray photoemission spectroscopy (XPS) equipped with a monochromatic Al Ka source (1486,7 eV) , overall resolution 0.9 eV;

• a chamber for the deposition of metals at room temperature.

Research Activity

The main research activity of the MBE group concentrates on semiconductor compound nanowires grown by molecular beam epitaxy.

Semiconductor nanowires are ideally 1-D nanostructures with diameter in the 10-100 nm range and in principle unconstrained length. Interest in these systems relies in the possibility they offer to exploit the properties related to their nano-scale size and their high surface to volume ratio in novel devices for electronics and optoelectronics.

Focus materials are III-V (GaAs, InAs, InGaAs) and II-VI (ZnSe, CdSe) compounds, and, very recently, on V2VI3topological insulator materials. The research activity concerns the understanding of the growth mechanism that leads to their highly anisotropic growth, the fabrication of radial (core/shell) or longitudinal nano-heterostructures, the growth of nanowire in homo- or hetero-epitaxial relationship with the substrate and of ordered array of identical wires, and the tuning of the nanowire electrical and magnetic properties by controlled incorporation of impurities.

We investigate the nanowire morphological, structural, optical and electronic properties, via scanning and transmission electron microscopy, Raman and photoluminescence spectroscopy, optical reflectivity, transport measurements and synchrotron radiation photoemission spectroscopy, in by house activity and thanks to collaborations.

Main collaborations

  • CNR IMM, Roma, Italy
  • Università la Sapienza, Roma, Italy
  • CNR IFN Roma, Italy
  • University of Nova Gorica, Ajduscina, Slovenja
  • ITMO University, St. Petersburg, Russia

Key publications

Advanced Functional Materials, 26-17:2836-2845, 2016 doi:10.1002/adfm.201504853

A Roadmap for Controlled and Efficient n-Type Doping of Self-Assisted GaAs Nanowires Grown by Molecular Beam Epitaxy

Orrù M., Repiso E., Carapezzi S., Henning A., Roddaro S., Franciosi A., Rosenwaks Y., Cavallini A., Martelli F., Rubini S.
Nano Letters, 16-5:3085-3093, 2016 doi:10.1021/acs.nanolett.6b00251

Long-Lived Hot Carriers in III-V Nanowires

Tedeschi D., De Luca M., Fonseka H.A., Gao Q., Mura F., Tan H.H., Rubini S., Martelli F., Jagadish C., Capizzi M., Polimeni A.
Physical Review B, 94-16, 2016 doi:10.1103/PhysRevB.94.165442

Ultrafast carrier dynamics band-gap renormalization and optical properties of ZnSe nanowires

Tian L., Di Mario L., Zannier V., Catone D., Colonna S., O'Keeffe P., Turchini S., Zema N., Rubini S., Martelli F.
Nano Letters, 17-11:6540-6547, 2017 doi:10.1021/acs.nanolett.7b02189

Addressing the Fundamental Electronic Properties of Wurtzite GaAs Nanowires by High-Field Magneto-Photoluminescence Spectroscopy

De Luca M., Rubini S., Felici M., Meaney A., Christianen P.C.M., Martelli F., Polimeni A.
Nanophotonics, 2019 doi:10.1515/nanoph-2019-0025

Plasmon-assisted bandgap engineering in dilute nitrides

Pettinari G., Labbate L.A., Sharma M.S., Rubini S., Polimeni A., Felici M.
Journal of Physical Chemistry C, 124-32:17783-17794, 2020 doi:10.1021/acs.jpcc.0c03216

Ga<inf>2</inf>Se<inf>3</inf>Nanowires via Au-Assisted Heterovalent Exchange Reaction on GaAs

Berto F., Haghighian N., Ferfolja K., Gardonio S., Fanetti M., Martelli F., Mussi V., Dubrovskii V.G., Shtrom I.V., Franciosi A., Rubini S.