Abstract
In this study, we fabricate high-quality epitaxial (LCO) thin films on substrates with different orientations and systematically investigate the change in the crystal orientation of thin-film grains by tuning the oxygen deposition pressure. Further tensile strain study reveals the depth dependence in these epitaxial LCO thin films. Further, synaptic transistors are fabricated based on these high-quality epitaxial LCO films, and long-duration nonvolatile potentiation and depression states are established. By reducing the thickness of the LCO channel, the signal-to-noise ratio of the nonvolatile switching is substantially improved. Changes in the potentiation and depression states are found to significantly depend on the lattice orientation of the LCO channel, suggesting that an anisotropic Li-ion diffusion rate in highly crystallized LCO films plays an important role in the device performance.
- Received 9 April 2021
- Accepted 26 October 2021
DOI:https://doi.org/10.1103/PhysRevMaterials.5.115401
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