Transparent conductive oxide TCO buffer layer effect on the resistive switching process in metal TCO TiO2 metal assemblies

摘要

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