Strategic allocation of two-dimensional van der Waals semiconductor as an oxygen reservoir for boosting resistive switching reliability

• SnS 2 thin film of the 2-dimensional structure was incorporated in two ways to the TiO 2 resistive switching layer. • The significant improvement of endurance performance in the resistive switching phenomenon was demonstrated with SnS 2 thin film. • From the microscopic analyses of materials, the co-stacked SnS 2 layer gives a role of oxygen reservoir layer in the manner of oxygen intercalation in its interlayer space. • It was revealed that the 2-dimensional thin film can be adopted as an oxygen reservoir layer in the resistive switching device without the consideration of the chemical relationship between them. 2-dimensional materials are highlighted in various electronic device applications due to their tunable and unique anisotropic physical characteristics induced by inherent low-dimensional nature. Herein, a 2-dimensional layered structure of SnS 2 is rationally adopted as an oxygen reservoir layer in a typical transition metal oxide based resistive switching device. The resistive switching media of stacked SnS 2 /TiO 2 and lamella-like SnS 2 ·TiO 2 show 100 and 250 times higher endurance characteristics than that of individual TiO 2 based resistive switching device, respectively. Additionally, the characteristic of the operation voltage distribution for resistive switching also exhibits improved homogeneity in SnS 2 -incorporated devices. Through the various microscopic analyses, it is revealed that the SnS 2 can store the mobile oxygen ions from TiO 2 in its interlayer, which facilitates boosted resistive switching characteristics. The oxygen reservoir layer is a crucial prerequisite for a reliable resistive switching device, however, the choice of materials that can serve as an oxygen reservoir is limited depending on the specific resistive switching system being used. This study demonstrates the 2-dimensional materials can be an unprecedented candidate for oxygen reservoir layers in resistive switching devices.