Ion irradiation defect engineering modulates thermal transport in MoS2/Si heterostructure

We investigate the thermal transport behavior in MoS2/Si (2D/3D) heterostructure through ion irradiation defect engineering, revealing differentiated regulation mechanisms for interfacial and in-plane heat transfer via multiscale methodologies. MoS2/Si, MoS2/V-Si(B) (bottom defects), and MoS2/V-Si(T) (top defects) were fabricated. Combined experimental measurements, finite element analysis, and molecular dynamics simulations confirm that V-Si(T) significantly enhances interfacial thermal conductance while reducing thermal conductivity of supported MoS2, whereas V-Si(B) concurrently improves both. The dynamic evolution process of Ar+ irradiation defects was reconstructed, and acoustic analysis with the frozen phonon method elucidates that irradiation-induced phonon-defect scattering enhances interfacial phonon coupling and creates additional transmission channels. V-Si(B) further promotes Rayleigh wave-to-bulk mode coupling, while V-Si(T) intensifies out-of-plane phonon scattering in MoS2, thereby suppressing in-plane heat transfer. The proposed ion irradiation strategy establishes an engineerable thermal management pathway with theoretical foundations for addressing heat dissipation bottlenecks in micro/nanoelectronic devices.