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Formation of a Selenide‐Based Heterostructure From a Designed Precursor †
Author(s) -
Falmbigl Matthias,
Esters Marco,
Johnson David C.
Publication year - 2017
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201700067
Subject(s) - superlattice , annealing (glass) , differential scanning calorimetry , crystallography , crystallization , heterojunction , materials science , monolayer , transmission electron microscopy , selenide , chemistry , nanotechnology , optoelectronics , physics , organic chemistry , selenium , composite material , thermodynamics , metallurgy
The formation of the ferecrystalline compound (SnSe) 1.15 VSe 2 is studied utilizing complementary X‐ray diffraction techniques, differential scanning calorimetry, compositional analysis, scanning transmission electron microscopy, and X‐ray absorption spectroscopy. A careful analysis unravels the formation mechanism, where a simultaneous crystallization of the individual constituents goes hand in hand with the formation of the superlattice structure. SnSe 2 monolayers form along with SnSe and VSe 2 units in the superlattice during the formation of (SnSe) 1.15 VSe 2 , with the SnSe 2 monolayers coexisting up to 300°C. An annealing temperature of 400°C is required to fully self‐assemble the ferecrystalline compound (SnSe) 1.15 VSe 2 , composed of alternating rocksalt‐like SnSe bilayers and VSe 2 trilayers. These results demonstrate a complex pathway along a multi‐valley energy landscape for these metastable compounds, which in turn offers a rich platform to synthesize targeted layering sequences by precisely controlling the composition of the precursors as well as the annealing conditions.