In‐gap states of In2O3 single crystals investigated by scanning tunneling spectroscopy

The influence of intrinsic point defects on the electronic structure of n‐type In2O3 single crystals grown by two methods, namely chemical vapor transport and from the melt, was examined by scanning tunneling spectroscopy. This method is a very surface sensitive technique for measuring the local density of states. So far not resolved states within the fundamental band gap have been observed. The gap states have been studied at different crystals and after several annealing treatments in an oxidizing atmosphere. The spectroscopic results will be compared to state of the art DFT‐calculations revealing hints on the origin of the gap states of In2O3 to be due to oxygen vacancies as well as indium and oxygen interstitials.

[1]  R. Uecker,et al.  Effect of heat treatment on properties of melt-grown bulk In2O3 single crystals , 2013 .

[2]  R. Egdell,et al.  Microscopic origin of electron accumulation in In2O3. , 2013, Physical review letters.

[3]  R. Manzke,et al.  Transport and angular resolved photoemission measurements of the electronic properties of In2O3 bulk single crystals , 2012 .

[4]  E. Lundgren,et al.  Bulk and surface characterization of In2O3(001) single crystals , 2012, 1804.04478.

[5]  A. Zunger,et al.  Surface origin of high conductivities in undoped In2O3 thin films. , 2012, Physical review letters.

[6]  Kazuhiro Kato,et al.  Changes in electrical and structural properties of indium oxide thin films through post-deposition annealing , 2011 .

[7]  C. Walle,et al.  Experimental electronic structure of In2O3 and Ga2O3 , 2011 .

[8]  A. Walsh.  Surface oxygen vacancy origin of electron accumulation in indium oxide , 2011 .

[9]  A. Gurlo,et al.  Nanosensors: towards morphological control of gas sensing activity. SnO2, In2O3, ZnO and WO3 case studies. , 2011, Nanoscale.

[10]  Gil U. Lee,et al.  Scanning probe microscopy. , 2010, Current opinion in chemical biology.

[11]  J. Medvedeva,et al.  Tuning the properties of complex transparent conducting oxides: Role of crystal symmetry, chemical composition, and carrier generation , 2010, 1002.4827.

[12]  P. Ágoston,et al.  Geometry, electronic structure and thermodynamic stability of intrinsic point defects in indium oxide , 2009, Journal of physics. Condensed matter : an Institute of Physics journal.

[13]  R. Egdell,et al.  Surface electron accumulation and the charge neutrality level in In2O3. , 2008, Physical review letters.

[14]  H. Fjellvåg,et al.  Phase stability, electronic structure, and optical properties of indium oxide polytypes , 2007 .

[15]  Stroscio,et al.  Atom-selective imaging of the GaAs(110) surface. , 1987, Physical review letters.

[16]  S. Kaneko,et al.  Crystal growth of SnO2 by chemical transport method , 1977 .

[17]  Steffen Ganschow,et al.  Melt growth, characterization and properties of bulk In2O3 single crystals , 2013 .

[18]  A. Janotti,et al.  Hydrogen multicentre bonds. , 2007, Nature materials.

[19]  N. Garcia,et al.  Scanning Tunneling Microscopy and Related Methods , 1990 .

[20]  R. L. Weiher,et al.  Optical Properties of Indium Oxide , 1966 .