Stoichiometric Bi(2)Se(3)topological insulator ultra-thin films obtained through a new fabrication process for optoelectronic applications
Journal article, 2020

A new fabrication process is developed for growing Bi(2)Se(3)topological insulators in the form of nanowires/nanobelts and ultra-thin films. It consists of two consecutive procedures: first Bi(2)Se(3)nanowires/nanobelts are deposited by standard catalyst free vapour-solid deposition on different substrates positioned inside a quartz tube. Then, the Bi2Se3, stuck on the inner surface of the quartz tube, is re-evaporated and deposited in the form of ultra-thin films on new substrates at a temperature below 100 degrees C, which is of relevance for flexible electronic applications. The method is new, quick, very inexpensive, easy to control and allows obtaining films with different thickness down to one quintuple layer (QL) during the same procedure. The composition and the crystal structure of both the nanowires/nanobelts and the thin films are analysed by different optical, electronic and structural techniques. For the films, scanning tunnelling spectroscopy shows that the Fermi level is positioned in the middle of the energy bandgap as a consequence of the achieved correct stoichiometry. Ultra-thin films, with thickness in the range 1-10 QLs deposited on n-doped Si substrates, show good rectifying properties suitable for their use as photodetectors in the ultra violet-visible-near infrared wavelength range.

Author

Matteo Salvato

University of Rome Tor Vergata

National Institute for Nuclear Physics

Mattia Scagliotti

University of Rome Tor Vergata

National Institute for Nuclear Physics

Maurizio De Crescenzi

University of Rome Tor Vergata

National Institute for Nuclear Physics

Paola Castrucci

University of Rome Tor Vergata

National Institute for Nuclear Physics

Fabio De Matteis

University of Rome Tor Vergata

Michele Crivellari

Fondazione Bruno Kessler (FBK)

Stefano Pelli Cresi

National Research Council of Italy (CNR)

Daniele Catone

National Research Council of Italy (CNR)

Thilo Bauch

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Floriana Lombardi

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Nanoscale

2040-3364 (ISSN)

Vol. 12 23 12405-12415

High Frequency Topological Insulator devices for Metrology (HiTIMe)

European Commission (EC), 2018-02-01 -- 2022-01-31.

Subject Categories

Inorganic Chemistry

Materials Chemistry

Condensed Matter Physics

DOI

10.1039/d0nr02725a

PubMed

32490504

More information

Latest update

9/18/2020