Defect-engineered 2D Bi2Se3-based broadband optoelectronic synapses with ultralow energy consumption for neuromorphic computing

Abstract

Optoelectronic synapses (OES) inspired by the human brain have gained attention in addressing the von Neumann bottleneck facing traditional computing. Numerous candidates, including topological insulators and other 2D materials, have been used to fabricate OES devices with different degrees of success. Se vacancies commonly appearing in epitaxially grown Bi2Se3 and importantly the ability to modulate the vacancies by changing the growth temperature make it a worthy candidate to construct an OES system. The vacancies effectively trap and release charges, leading to persistent photoconductivity, which is the mechanism behind OES operation. A defect-induced Bi2Se3-based synapse using an ultrathin layer grown by chemical vapor deposition is shown herein to successfully demonstrate basic synapse characteristics such as paired-pulse facilitation (PPF), short-term and long-term memory, and learning–relearning behavior. This OES device shows a very high PPF index of 201.7%, a long memory retention time of 523.1 s, and an ultralow energy consumption of 9.2 fJ per spike, which is at the low end of the 1–100 fJ range for biological systems. Density functional theory simulations reinforce the definite role of trap centers induced by the Se vacancies in the device operation. Our device realizes a high recognition accuracy of 90.12% for MNIST handwritten digital images in simulations based on an artificial neural network algorithm. The exceptional results achieved here show the potential of Bi2Se3 for synaptic applications and pave the way for exploiting its potential in future high-performance neuromorphic computing and other artificial visual perception systems.

Graphical abstract: Defect-engineered 2D Bi2Se3-based broadband optoelectronic synapses with ultralow energy consumption for neuromorphic computing

Supplementary files

Article information

Article type
Communication
Submitted
13 Nov 2024
Accepted
14 Mar 2025
First published
17 Mar 2025
This article is Open Access
Creative Commons BY-NC license

Mater. Horiz., 2025, Advance Article

Defect-engineered 2D Bi2Se3-based broadband optoelectronic synapses with ultralow energy consumption for neuromorphic computing

S. Nandi, S. Ghosal, M. Meyyappan and P. K. Giri, Mater. Horiz., 2025, Advance Article , DOI: 10.1039/D4MH01625D

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements