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@ARTICLE{Morgenbesser:484450,
      author       = {Morgenbesser, Maximilian and Viernstein, Alexander and
                      Schmid, Alexander and Herzig, Christopher and Kubicek,
                      Markus and Taibl, Stefanie and Bimashofer, Gesara and Stahn,
                      Jochen and Vaz, Carlos Antonio Fernandes and Döbeli, Max
                      and Biautti, Federico and de Dios Sirvent, Juan and Liedke,
                      Maciej Oskar and Butterling, Maik and Kamiński, Michał and
                      Tolkiehn, Martin and Vonk, Vedran and Stierle, Andreas and
                      Wagner, Andreas and Tarancon, Albert and Limbeck, Andreas
                      and Fleig, Jürgen},
      title        = {{U}nravelling the {O}rigin of {U}ltra‐{L}ow
                      {C}onductivity in {S}r{T}i{O}$_3$ {T}hin {F}ilms: {S}r
                      {V}acancies and {T}i on {A}‐{S}ites {C}ause {F}ermi
                      {L}evel {P}inning},
      journal      = {Advanced functional materials},
      volume       = {32},
      number       = {38},
      issn         = {1057-9257},
      address      = {Weinheim},
      publisher    = {Wiley-VCH},
      reportid     = {PUBDB-2022-06265},
      pages        = {2202226},
      year         = {2022},
      abstract     = {Different SrTiO$_3$ thin films are investigated to unravel
                      the nature of ultra-low conductivities recently found in
                      SrTiO$_3$ films prepared by pulsed laser deposition.
                      Impedance spectroscopy reveals electronically
                      pseudo-intrinsic conductivities for a broad range of
                      different dopants (Fe, Al, Ni) and partly high dopant
                      concentrations up to several percent. Using
                      inductively-coupled plasma optical emission spectroscopy and
                      reciprocal space mapping, a severe Sr deficiency is found
                      and positron annihilation lifetime spectroscopy revealed Sr
                      vacancies as predominant point defects. From
                      synchrotron-based X-ray standing wave and X-ray absorption
                      spectroscopy measurements, a change in site occupation is
                      deduced for Fe-doped SrTiO$_3$ films, accompanied by a
                      change in the dopant type. Based on these experiments, a
                      model is deduced, which explains the almost ubiquitous
                      pseudo-intrinsic conductivity of these films. Sr deficiency
                      is suggested as key driver by introducing Sr vacancies and
                      causing site changes (Fe$_{Sr}$ and Ti$_{Sr}$) to
                      accommodate nonstoichiometry. Sr vacancies act as mid-gap
                      acceptor states, pinning the Fermi level, provided that
                      additional donor states (most probably
                      Ti$_{Sr}^{\bullet\bullet}$) are present. Defect chemical
                      modeling revealed that such a Fermi level pinning also
                      causes a self-limitation of the Ti site change and leads to
                      a very robust pseudo-intrinsic situation, irrespective of
                      Sr/Ti ratios and doping.},
      cin          = {DOOR ; HAS-User / FS-PETRA-D / FS-NL},
      ddc          = {530},
      cid          = {I:(DE-H253)HAS-User-20120731 /
                      I:(DE-H253)FS-PETRA-D-20210408 / I:(DE-H253)FS-NL-20120731},
      pnm          = {632 - Materials – Quantum, Complex and Functional
                      Materials (POF4-632) / 6G3 - PETRA III (DESY) (POF4-6G3)},
      pid          = {G:(DE-HGF)POF4-632 / G:(DE-HGF)POF4-6G3},
      experiment   = {EXP:(DE-H253)P-P24-20150101},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000821635900001},
      doi          = {10.1002/adfm.202202226},
      url          = {https://bib-pubdb1.desy.de/record/484450},
}