Extended Data Fig. 5: DFT calculations of the binding energies between vertical/horizontal 2D Bi2O2Se islands on LaAlO3 (100) and MgO (110) substrates.
From: 2D fin field-effect transistors integrated with epitaxial high-k gate oxide
a,b, Optimized structures of 2D layered Bi2O2Se islands on the LaAlO3 (100) surface, in which the difference of interfacial interactions is also shown. The calculations showed direct edge bonding of the unsaturated \({[{{\rm{Bi}}}_{2}{{\rm{O}}}_{2}]}_{{n}}^{2{n}+}\) layers to substrate in the vertical nucleation process of 2D Bi2O2Se fins. c, DFT calculations of the binding energies of a Bi2O2Se island with different nucleation types on the LaAlO3 (100) and MgO (110) surfaces. The results clearly showed that, on the LaAlO3 (100) and MgO (110) surfaces, the vertically aligned 2D Bi2O2Se is much more stable than the horizontally aligned one by direct bonding to the epitaxial surface through the \({[{{\rm{Bi}}}_{2}{{\rm{O}}}_{2}]}_{{n}}^{2{n}+}\) layer edge. We conclude that the nucleation of vertical 2D Bi2O2Se is governed by an edge-bonding-guided mechanism.
