Spectroscopic properties of few-layer tin chalcogenides

Antoine Dewandre, Matthieu Jean Verstraete, Nicole Grobert, Zeila Zanolli
2019 Journal of Physics Materials  
Stable structures of layered SnS and SnSe and their associated electronic and vibrational spectra are predicted using first-principles DFT calculations. The calculations show that both materials undergo a phase transformation upon thinning whereby the in-plane lattice parameters ratio a/b converges towards 1, similar to the high-temperature behaviour observed for their bulk counterparts. The electronic properties of layered SnS and SnSe evolve to an almost symmetric dispersion whilst the gap
more » ... nges from indirect to direct. Characteristic signatures in the phonon dispersion curves and surface phonon states where only atoms belonging to surface layers vibrate should be observable experimentally.
doi:10.1088/2515-7639/ab3513 fatcat:yukctwyuv5hhxgbbdpfngbtvka