Percolation threshold enables optical resistive‐memory switching and light‐tuneable synaptic learning in segregated nanocomposites

Jaafar, Ayoub H.; O'Neill, Mary; Kelly, Stephen M.; Verrelli, Emanuele; Kemp, Neil T.

Abstract

An optical memristor where the electrical resistance memory depends on the history of both the current flowing through the device and the irradiance of incident light onto it is demonstrated. It is based on a nanocomposite consisting of functionalized gold nanoparticles in an optically active azobenzene polymer matrix. The composite has an extremely low percolation threshold of 0.04% by volume for conductivity because of the aggregation of the conducting nanoparticles into filamentary nanochannels. Optical irradiation results in photomechanical switching through expansion of the thin film from above to below the percolation threshold, giving a large LOW/HIGH resistance ratio of 103. The device acts as an artificial synapse, the conductivity or plasticity of which can be independently modulated, either electrically or optically, to enable tunable and reconfigurable synaptic circuits for brain‐inspired artificial intelligent or visual memory arrays. The lifetime of the resistive‐memory states is also optically controllable, which enables spatial modulation of long‐ and short‐term memory.

Citation

Jaafar, A. H., O'Neill, M., Kelly, S. M., Verrelli, E., & Kemp, N. T. (2019). Percolation threshold enables optical resistive‐memory switching and light‐tuneable synaptic learning in segregated nanocomposites. Advanced Electronic Materials, 5(7), Article 1900197. https://doi.org/10.1002/aelm.201900197

• Journal Article Type: Article
• Acceptance Date: May 2, 2019
• Online Publication Date: May 28, 2019
• Publication Date: Jul 1, 2019
• Deposit Date: Jul 3, 2019
• Publicly Available Date: May 29, 2020
• Journal: Advanced Electronic Materials
• Print ISSN: 2199-160X
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Issue: 7
• Article Number: 1900197
• DOI: https://doi.org/10.1002/aelm.201900197
• Keywords: Electronic, Optical and Magnetic Materials
• Public URL: https://hull-repository.worktribe.com/output/1866750
• Publisher URL: https://onlinelibrary.wiley.com/doi/abs/10.1002/aelm.201900197
• Contract Date: Jul 3, 2019