In-plane Moiré effect for boosting near-field radiative heat transfer

We present a novel in-plane Moiré effects based on monolayer 1D MoO₃ gratings. By aligning the crystal axes of adjacent gratings orthogonally, the in-plane hybridization of hyperbolic and elliptical phonon polaritons in a single material is achieved to enhance near-field radiative heat transfer. Using rigorous coupled-wave analysis and finite element simulations, the reflection/transmission coefficients and near-field radiative heat flux are calculated. Results demonstrate that the hyperbolic-elliptical hybridized phonon polaritons (HE-HyPhPs) overcome intrinsic Reststrahlen band constraints, establishing efficient broadband energy transport channels that significantly boost heat flux. Furthermore, the hybridized mode is precisely tunable via geometric parameters. This approach provides new insights and theoretical support for designing high performance near-field thermal management devices.