Cation-Intercalated Mott Insulator α-RuCl3 Superlattice for Actively Tuned Optoelectronics

Abstract Active tuning of the spectral response within sensing materials is critical for application-specific optoelectronics. However, current approaches typically suffer from limited tunability, complex architectures, or sacrificed stability. Here we report an on-chip cation intercalation strategy that transforms the Kitaev-candidate Mott insulator α-ruthenium chloride (α-RuCl3) into a tetramethylammonium (TMA+)-intercalated RuCl3 layered superlattice. The intercalation-induced reconstruction of the Mott-derived electronic states substantially narrows the optical gap from ∼1.1 eV to ∼0.6 eV, extending the spectral response into the short-wave infrared (SWIR) regime. The introduction of an in situ van der Waals tunneling barrier suppresses dark current by >3 orders of magnitude and enhances specific detectivity by 4–6 orders of magnitude. By employing machine learning models, we demonstrate device-response-guided image processing for intelligent recognition under degraded environments. This work establishes a connection between correlated-electron systems and intelligent sensing, stimulating research directions at the intersection of quantum materials, optoelectronics, and intelligent sensing systems.