1. Sensor Technology Research Center; University of Sussex; Falmer Brighton BN1 9QT UK
2. Electronics Laboratory; ETH Zürich; 8092 Zürich Switzerland
3. Institute for Integrative Nanosciences; Institute for Solid State and Materials Research Dresden (IFW Dresden); 01069 Dresden Germany
4. Material Systems for Nanoelectronics; Chemnitz University of Technology; 09107 Chemnitz Germany
5. Center for Advancing Electronics Dresden; Dresden University of Technology; 01062 Dresden Germany
6. Helmholtz-Zentrum Dresden-Rossendorf; Institute of Ion Beam Physics and Materials Research; 01328 Dresden Germany