Tracking the Movement of Dopants in an Analog Memristor using X-ray Absorption Spectroscopy

1. Tracking the Movement of Dopants in an Analog Memristor using X-ray Absorption Spectroscopy Dennis W. Hess, Georgia Tech Research Corporation, DMR 0820382 Use this space for another picture, graphic or figure Schematic density of states for a layered trigonal prismatic semiconductor (left), LiNbO2. The states above the Fermi level are probed using XAS and change as lithium dopants are redistributed across an LiNbO2 memristor under the application of a bias. • Analog memristors based on semiconducting LiNbO2 have been characterized using X-ray Absorption Spectroscopy (XAS). We have identified the underlying analog memristance mechanism as the gradual movement of lithium in the device in response to an applied bias. By identifying the physical memristance mechanism in analog LiNbO2 memristors, device modifications including the use of an electrolyte have been identified to vary the memory permanence of the device. Normalized X-ray Absorption Spectroscopy (XAS) of an as-grown (blue) and 2.0 V biased (green) LiNbO2 memristor. Five regions are collected across the device where the spectra labeled “1” is closest to the positively biased contact and the spectra labeled “5” is closest to the grounded contact of the device. Sponsored by NSF-MRSEC through contract DMR-0820382