Fangzhou Zhao, Ding Wang, Haotuo Liu, Xiaohu Wu, Haoqiang Ai
Thermophotovoltaic systems, which convert high-temperature thermal radiation into electricity, offer considerable potential for efficient power generation and waste-heat recovery. However, most high-performance selective emitters rely on lithographically patterned micro-nanostructures, resulting in fabrication complexity and limited scalability. In this work, a multilayer Fabry-Pérot selective emitter consisting of alternating W and Al2O3 thin films is proposed for efficient thermophotovoltaic energy conversion. By tailoring periodic Fabry-Pérot resonances within a simple planar multilayer film, the emission spectrum is precisely matched to internal quantum efficiency of GaInAsSb photovoltaic cells. Numerical results show that optimized emitter achieves an average emissivity of 0.961 in 0.75-2.54 μm wavelength range, corresponding to an emitter efficiency of 97.41%, a photovoltaic cell efficiency of 23.19%, and a thermoelectric conversion efficiency of 22.59% for thermophotovoltaic system. Electric-field distributions reveal that selective emission originates from coupling of Fabry-Pérot resonances supported by the multilayer cavity. Furthermore, thickness parameter analyses demonstrate that proposed emitter exhibits strong tolerance to fabrication-induced dimensional variations. The emitter also exhibits strong angular stability, maintaining average emissivity above 0.94 under transverse magnetic polarization at 60° incidence and above 0.91 under transverse electric polarization at 50° incidence within the target wavelength range. Combining excellent performance with simple fabrication, the proposed emitter offers a scalable and cost-effective solution for high-performance thermophotovoltaic systems.