Axion-field-enhanced near-field thermophotovoltaic systems with band dislocation

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 quasiflat 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 ×10⁴ 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.