Molecular precursor-directed growth of nanostructured SnS2 for memristive and neuromorphic electronics

Abstract

Low-dimensional layered metal chalcogenides have recently garnered significant attention for advanced electronic and optoelectronic applications, particularly memristive and synaptic devices; however, achieving purity and scalable fabrication remains a key challenge. We demonstrate a facile and scalable in situ solvothermal approach enabling low-temperature deposition of SnS₂ thin films, employing the single-source precursor (SSP) [Cl₂Sn(S₂P(OⁱC₃H₇)₂)₂]. The distorted octahedral complex [Cl₂Sn(S₂P(OⁱC₃H₇)₂)₂], derived from SnCl₄, serves as an efficient SSP for solvothermal growth of SnS₂ on ITO. The films exhibit phase-pure hexagonal crystallinity with well-defined composition and morphology, and an optical bandgap of 2.06 eV. Leveraging this synthesis route, Ag/SnS₂/ITO memristive device was fabricated, exhibiting electroforming-free bipolar resistive switching at ±0.6 V. The device demonstrated stable endurance over more than 10² cycles with an ON/OFF ratio of ∼10. Additionally, the device further exhibits analogue conductance modulation and synaptic plasticity, enabling emulation of biological learning behaviour when implemented in a hardware-aware artificial neural network. The experimentally derived weight update dynamics achieved 92% classification accuracy on the MNIST dataset. Collectively, these findings establish SSP-derived SnS₂ thin films as a viable material platform for emerging memory and neuromorphic electronics.