@article{GabelPickemScheidereretal.2022, author = {Gabel, Judith and Pickem, Matthias and Scheiderer, Philipp and Dudy, Lenart and Leikert, Berengar and Fuchs, Marius and St{\"u}binger, Martin and Schmitt, Matthias and K{\"u}spert, Julia and Sangiovanni, Giorgio and Tomczak, Jan M. and Held, Karsten and Lee, Tien-Lin and Claessen, Ralph and Sing, Michael}, title = {Toward Functionalized Ultrathin Oxide Films: The Impact of Surface Apical Oxygen}, series = {Advanced Electronic Materials}, volume = {8}, journal = {Advanced Electronic Materials}, number = {4}, issn = {2199-160X}, doi = {10.1002/aelm.202101006}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318914}, year = {2022}, abstract = {Thin films of transition metal oxides open up a gateway to nanoscale electronic devices beyond silicon characterized by novel electronic functionalities. While such films are commonly prepared in an oxygen atmosphere, they are typically considered to be ideally terminated with the stoichiometric composition. Using the prototypical correlated metal SrVO\(_{3}\) as an example, it is demonstrated that this idealized description overlooks an essential ingredient: oxygen adsorbing at the surface apical sites. The oxygen adatoms, which are present even if the films are kept in an ultrahigh vacuum environment and not explicitly exposed to air, are shown to severely affect the intrinsic electronic structure of a transition metal oxide film. Their presence leads to the formation of an electronically dead surface layer but also alters the band filling and the electron correlations in the thin films. These findings highlight that it is important to take into account surface apical oxygen or—mutatis mutandis—the specific oxygen configuration imposed by a capping layer to predict the behavior of ultrathin films of transition metal oxides near the single unit-cell limit.}, language = {en} }