@inproceedings{HaeberleGasparBarquinhaetal., author = {Haeberle, J{\"o}rg and Gaspar, Diana and Barquinha, Pedro and Pereira, Lu{\´i}s and Martins, Rodrigo and Fortunato, Elvira and Machulik, Stephan and Janowitz, Christoph and Manzke, Recardo and Schmeißer, Dieter}, title = {The Electronic Structure of amorphuos SnOx thin films and SnO2 single crystals}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 271}, abstract = {We compare the electronic properties of amorphous p-type SnOx thin film grown by rf magnetron sputtering with those of n-type SnO2 single crystals grown by cvt. We use resPES to study the electronic band structure. We measure the core levels, the VB PES data, partial Integrated Yield (pIY) and the XAS absorption data. From the resPES data recorded at the O1s and the Sn3d edges we derive the VB pDOS and the CB pDOS . The differences are most pronounced in the position of the VBM as for the a-SnOx films there appears a band closer to the Fermi energy. In addition for the SnOx we find in the XAS and pIY data a significant peak that appears right at the Fermi energy. This peak is absent in the single crystalline data. We attribute this to a change in the configuration of the Sn4d states to form a 4d8 configuration instead of 4d9 and 4d10 configurations which are identified in the single crystalline data.}, language = {en} } @misc{HaeberleMachulikJanowitzetal., author = {Haeberle, J{\"o}rg and Machulik, Stephan and Janowitz, Christoph and Manzke, Recardo and Gaspar, Diana and Barquinha, Pedro and Schmeißer, Dieter}, title = {Gap states in the electronic structure of SnO2 single crystals and amorphous SnOxthin films}, series = {Journal of Applied Physics}, volume = {120}, journal = {Journal of Applied Physics}, number = {10}, issn = {0021-8979}, doi = {10.1063/1.4962313}, pages = {105101-1 -- 105101-13}, abstract = {The electronic structure of a SnO2 single crystal is determined by employing resonant photoelectron spectroscopy. We determine the core level, valence band, and X-ray absorption (XAS) data and compare these with those of amorphous SnOx thin films. We find similar properties concerning the data of the core levels, the valence band features, and the absorption data at the O1s edge. We find strong signals arising from intrinsic in-gap states and discuss their origin in terms of polaronic and charge-transfer defects. We deduce from the XAS data recorded at the Sn3d edge that the Sn4d10 ground state has contributions of 4d9 and 4d8 states due to configuration interaction. We identify localized electronic states depending on the strength of the 4d-5s5p interaction and of the O2p-to-Sn4d charge-transfer processes, both appear separated from the extended band-like states of the conduction band. For the amorphous SnOx thin films, significant differences are found only in the absorption data at the Sn3d-edge due to a stronger localization of the in-gap states.}, language = {en} } @incollection{HenkelHaeberleMuelleretal., author = {Henkel, Karsten and Haeberle, J{\"o}rg and M{\"u}ller, Klaus and Janowitz, Christoph and Schmeißer, Dieter}, title = {Preparation, properties and electronic structure of SnO₂}, series = {Single Crystals of Electronic Materials}, booktitle = {Single Crystals of Electronic Materials}, editor = {Fornari, Robert}, publisher = {Elsevier, Woodhead Publishing}, address = {Duxford}, isbn = {978-0-08-102096-8}, pages = {547 -- 572}, abstract = {This chapter reports about tin oxide (SnO₂), a material which belongs to the transparent conducting oxide family and is best characterized by its high conductivity, high carrier mobility, and the ability to form p-type conductivity. We correlate these properties in terms of localized intrinsic electronic defect states which are resolved by resonant photoelectron spectroscopy measurements. We describe SnO₂ in terms of an inhomogeneous, mixed-ionic-covalent semiconductor in which these intrinsic electronic defects state are stabilized.}, language = {en} }