Axion-Field-Enhanced Near-Field Thermophotovoltaic Systems with Band Dislocation

Abstract We propose a near-field thermophotovoltaic system utilizing magnetic Weyl semimetals, which exhibit a distinct gyrotropic effect originating from their intrinsic axion field. Critically, we demonstrate that intentional band dislocation, achieved by layer-specific tuning of the chemical potential, significantly enhances the energy-conversion efficiency. This effect arises from the formation of quasi-flat bands in momentum space, which broaden the spectral heat flux and amplify photon tunneling above the bandgap. At optimized chemical potential mismatches, the system achieves a 65% Carnot efficiency and a power density of 7 × 10 4 W⋅m −2 , surpassing symmetric configurations by 7%. The optimization of the Weyl semimetals thickness further demonstrates a clear tuning window where both the output power and energy-conversion efficiency are significantly improved. These results establish chemical-potential engineering toward high-efficiency near-field thermophotovoltaics for waste heat recovery and infrared energy applications.