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Neuromorphic Photoresponse in Ultrathin SnS2-Based Field Effect Transistor

De Stefano, Sebastiano ; Durante, Ofelia ; Sessa, Andrea ; Politano, Antonio ; D’Olimpio, Gianluca ; Dadiani, Tsotne ; Faella, Enver ; Dinescu, Adrian ; Parvulescu, Catalin and Hetherington, Crispin LU orcid , et al. (2025) In ACS Applied Materials and Interfaces 17(36). p.50901-50915
Abstract

As artificial intelligence continues to evolve, neuromorphic technologies, which emulate biological neural networks, are increasingly seen as a promising direction. Two-dimensional materials are considered promising for neuromorphic applications due to their tunable electrical and optoelectronic properties. In this work, a back-gated tin disulfide (SnS2) field-effect transistor (FET) is electrically and optoelectronically characterized at different temperatures (80, 295, and 380 K), pressures (ambient and 10–4mbar), and illumination conditions (dark and laser light from 420 to 800 nm). Responsivity peaks of up to ∼100 A/W are recorded. Persistent photoconductivity is observed, with current retention after... (More)

As artificial intelligence continues to evolve, neuromorphic technologies, which emulate biological neural networks, are increasingly seen as a promising direction. Two-dimensional materials are considered promising for neuromorphic applications due to their tunable electrical and optoelectronic properties. In this work, a back-gated tin disulfide (SnS2) field-effect transistor (FET) is electrically and optoelectronically characterized at different temperatures (80, 295, and 380 K), pressures (ambient and 10–4mbar), and illumination conditions (dark and laser light from 420 to 800 nm). Responsivity peaks of up to ∼100 A/W are recorded. Persistent photoconductivity is observed, with current retention after illumination ranging from 0% to ∼30% of the initial dark current, depending on temperature and gate voltage. The underlying microscopic mechanisms are analyzed, revealing a key role for trap states and ambient adsorbates, and a qualitative model is proposed to explain the observed effects. Trap states within the bandgap, often considered detrimental, are exploited to induce synaptic plasticity, with synaptic weight changes tunable from 0.001 to 3000. Temperature and gate voltage are found to be effective parameters for modulating plasticity, enabling smooth transitions between short-term and long-term behavior. These results clarify the microscopic origin of plasticity in SnS2, demonstrate its robustness under realistic conditions, and lay the foundation for the integration of this two-dimensional material into next-generation neuromorphic architectures.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
2D materials, field-effect transistors, neuromorphic, photoresponse, trap states
in
ACS Applied Materials and Interfaces
volume
17
issue
36
pages
15 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:105015477886
  • pmid:40857078
ISSN
1944-8244
DOI
10.1021/acsami.5c11651
language
English
LU publication?
yes
id
71ce58f5-610f-4d51-b5d2-fd0d7586f838
date added to LUP
2025-10-15 10:55:10
date last changed
2025-11-26 14:13:25
@article{71ce58f5-610f-4d51-b5d2-fd0d7586f838,
  abstract     = {{<p>As artificial intelligence continues to evolve, neuromorphic technologies, which emulate biological neural networks, are increasingly seen as a promising direction. Two-dimensional materials are considered promising for neuromorphic applications due to their tunable electrical and optoelectronic properties. In this work, a back-gated tin disulfide (SnS<sub>2</sub>) field-effect transistor (FET) is electrically and optoelectronically characterized at different temperatures (80, 295, and 380 K), pressures (ambient and 10<sup>–4</sup>mbar), and illumination conditions (dark and laser light from 420 to 800 nm). Responsivity peaks of up to ∼100 A/W are recorded. Persistent photoconductivity is observed, with current retention after illumination ranging from 0% to ∼30% of the initial dark current, depending on temperature and gate voltage. The underlying microscopic mechanisms are analyzed, revealing a key role for trap states and ambient adsorbates, and a qualitative model is proposed to explain the observed effects. Trap states within the bandgap, often considered detrimental, are exploited to induce synaptic plasticity, with synaptic weight changes tunable from 0.001 to 3000. Temperature and gate voltage are found to be effective parameters for modulating plasticity, enabling smooth transitions between short-term and long-term behavior. These results clarify the microscopic origin of plasticity in SnS<sub>2</sub>, demonstrate its robustness under realistic conditions, and lay the foundation for the integration of this two-dimensional material into next-generation neuromorphic architectures.</p>}},
  author       = {{De Stefano, Sebastiano and Durante, Ofelia and Sessa, Andrea and Politano, Antonio and D’Olimpio, Gianluca and Dadiani, Tsotne and Faella, Enver and Dinescu, Adrian and Parvulescu, Catalin and Hetherington, Crispin and Kuo, Chia Nung and Lue, Chin Shan and Aldrigo, Martino and Passacantando, Maurizio and Di Bartolomeo, Antonio}},
  issn         = {{1944-8244}},
  keywords     = {{2D materials; field-effect transistors; neuromorphic; photoresponse; trap states}},
  language     = {{eng}},
  number       = {{36}},
  pages        = {{50901--50915}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Applied Materials and Interfaces}},
  title        = {{Neuromorphic Photoresponse in Ultrathin SnS<sub>2</sub>-Based Field Effect Transistor}},
  url          = {{http://dx.doi.org/10.1021/acsami.5c11651}},
  doi          = {{10.1021/acsami.5c11651}},
  volume       = {{17}},
  year         = {{2025}},
}