TY  - JOUR
AU  - Cho, Deok-Yong
AU  - Kim, Ki-jeong
AU  - Lee, Kug-Seung
AU  - Lübben, Michael
AU  - Chen, Shaochuan
AU  - Valov, Ilia
TI  - Chemical Influence of Carbon Interface Layers in Metal/Oxide Resistive Switches
JO  - ACS applied materials & interfaces
VL  - 15
IS  - 14
SN  - 1944-8244
CY  - Washington, DC
PB  - Soc.
M1  - FZJ-2023-01766
SP  - 18528–18536
PY  - 2023
AB  - Thin layers introduced between a metal electrode and a solid electrolyte can significantly alter the transport of mass and charge at the interfaces and influence the rate of electrode reactions. C films embedded in functional materials can change the chemical properties of the host, thereby altering the functionality of the whole device. Using X-ray spectroscopies, here we demonstrate that the chemical and electronic structures in a representative redox-based resistive switching (RS) system, Ta2O5/Ta, can be tuned by inserting a graphene or ultrathin amorphous C layer. The results of the orbitalwise analyses of synchrotron Ta L3-edge, C K-edge, and O K-edge X-ray absorption spectroscopy showed that the C layers between Ta2O5 and Ta are significantly oxidized to form COx and, at the same time, oxidize the Ta layers with different degrees of oxidation depending on the distance: full oxidation at the nearest 5 nm Ta and partial oxidation in the next 15 nm Ta. The depth-resolved information on the electronic structure for each layer further revealed a significant modification of the band alignments due to C insertion. Full oxidation of the Ta metal near the C interlayer suggests that the oxygen-vacancy-related valence change memory mechanism for the RS can be suppressed, thereby changing the RS functionalities fundamentally. The knowledge on the origin of C-enhanced surfaces can be applied to other metal/oxide interfaces and used for the advanced design of memristive devices.
LB  - PUB:(DE-HGF)16
C6  - 36989142
UR  - <Go to ISI:>//WOS:000962869300001
DO  - DOI:10.1021/acsami.3c00920
UR  - https://juser.fz-juelich.de/record/1006633
ER  -