• Filatova, E.O.; Baraban, A.P.; Konashuk, A.S.; Konyushenko, M.A.; Selivanov, A.A.; Sokolov, A.A.; Schäfers, F.; Drozd, V.E.: Transparent-conductive-oxide (TCO) buffer layer effect on the resistive switching process in metal/TCO/TiO2/metal assemblies. New Journal of Physics 16 (2014), p. 113014/1-15

10.1088/1367-2630/16/11/113014
Open Access Version

Abstract:
The effect of transparent-conductive-oxide (TCO) buffer layer on the insulator matrix and on the resistive switching process in the metal/TiO2/TCO/metal assembly was studied depending on the material of TCO (ITO - (In2O3)0.9(SnO2)0.1 or SnO2 or ZnO). First time electro-physical studies and near edge x-ray absorption fine structure (NEXAFS) studies were carried out jointly and in the same point of the sample providing the direct experimental evidence that switching process influences strongly the lowest unoccupied bands and local atomic structure of the TiO2 layers. It was established that TCO layer in metal/TiO2/TCO/metal assembly is an additional source of oxygen vacancies for TiO2 film. The RL (RH) states are achieved presumably with formation (rupture) of electrically conductive path of oxygen vacancies. The inserting the Al2O3 thin layer between TiO2 and TCO layers restricts to some extent processes of migration of oxygen ions and vacancies and does not permit to realize the anti-clockwise bipolar resistive switching in Au/TiO2/Al2O3/ITO/Au assembly. The greatest value of the ratio RH/RL is observed for assembly with SnO2 buffer layer that will provide to implement the maximum set of intermediate states (recording analog data) and increases the density of information recording in this case.