SrTiO(3) substrates capped with a GaAs monolayer: An ab initio study

François Bottin (1) , Fabio Finocchi (1)

1 INSP - Institut des Nanosciences de Paris

The epitaxy of GaAs monolayers on SrTiO(3) substrates is studied by extensive first-principles simulations, considering both cleavage (100) and polar (110) orientations of SrTiO(3) with distinct terminations, and several adsorption sites for the overlayer. Large charge transfers take place for the two SrTiO(110)/GaAs and O(2)-(110)/GaAs polar heterojunctions, at variance with other substrate terminations, which are polar compensated by construction. As a function of the thermodynamic conditions, the formation of mixed compounds at the interface can be avoided. Relying on the interfacial energy, we predict that the GaAs monolayer is much more stable on (110) than on (100) surfaces, consistent with the available experimental results. Moreover, it should wet both SrTiO and Sr terminations of SrTiO(3)(110).

Domaines: Matière Condensée [cond-mat]

François Bottin, Fabio Finocchi. SrTiO(3) substrates capped with a GaAs monolayer: An ab initio study. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2007, 76 (16), pp.165427. ⟨10.1103/PhysRevB.76.165427⟩. ⟨hal-01293291⟩