Band gap expansion, shear inversion phase change behaviour and low-voltage induced crystal oscillation in low-dimensional tin selenide crystals.

Abstract

In common with rocksalt-type alkali halide phases and also semiconductors such as GeTe and SnTe, SnSe forms all-surface two atom-thick low dimensional crystals when encapsulated within single walled nanotubes (SWNTs) with diameters below ∼1.4 nm. Whereas previous density functional theory (DFT) studies indicate that optimised low-dimensional trigonal HgTe changes from a semi-metal to a semi-conductor, low-dimensional SnSe crystals typically undergo band-gap expansion. In slightly wider diameter SWNTs (∼1.4-1.6 nm), we observe that three atom thick low dimensional SnSe crystals undergo a previously unobserved form of a shear inversion phase change resulting in two discrete strain states in a section of curved nanotube. Under low-voltage (i.e. 80-100 kV) imaging conditions in a transmission electron microscope, encapsulated SnSe crystals undergo longitudinal and rotational oscillations, possibly as a result of the increase in the inelastic scattering cross-section of the sample at those voltages.

DOI: 10.1039/c4dt00185k

Cite this paper

@article{Carter2014BandGE, title={Band gap expansion, shear inversion phase change behaviour and low-voltage induced crystal oscillation in low-dimensional tin selenide crystals.}, author={Robin Carter and Mikhail V Suyetin and Samantha Lister and Mike Dyson and Harrison Trewhitt and Sanam Goel and Zheng Liu and Kazu Suenaga and Cristina E. Giusca and Reza J. Kashtiban and John L. Hutchison and John Dore and G. R. Bell and Elena Bichoutskaia and J . G . Sloan}, journal={Dalton transactions}, year={2014}, volume={43 20}, pages={7391-9} }