This work theoretically studies a spectrally selective nanophotonic cell based on an asymmetric Fabry-Perot resonance cavity structure with sub-100-nm GaSb layer for improving the thermophotovoltaic (TPV) energy conversion performance. The simulated spectral property of the ultrathin metafilm cell structure exhibits a high absorption peak above the bandgap due to the interference effect with electromagnetic field enhanced inside the GaSb layer between top and bottom silver electrodes, while the sub-bandgap absorption is as low as a few percent because of high reflectivity of the metal. An absorption enhancement nearly 20 times at particular frequency above bandgap is achieved within the sub-100-nm GaSb layer with the nanophotonic cell structure compared to the free-standing one. Besides, a thin layer of MoO_x is incorporated into the metafilm cell structure as a hole transport layer to consider the charge collection in practice. With rigorous optoelectronic analysis by considering both radiative and nonradiative recombinations (Shockley-Read-Hall and Auger), the nanophotonic cell is predicted to achieve a TPV efficiency of 22.8% and output power of 0.62 W/cm² with a black emitter at 1500 K due to spectrally enhanced in-band absorption and low sub-bandgap absorption. With an ideal selective emitter the efficiency can be further improved to 28% by eliminating sub-bandgap photons. While selective emitters still endure the challenges in perfect spectral emittance and high-temperature stability in practice, the proposed wavelength-selective nanophotonic metafilm cell could be a viable route to achieve high-efficiency and low-cost TPV energy conversion.

这项工作理论上研究了基于不对称Fabry-Perot谐振腔结构的光谱选择性纳米光子电池，该结构具有100nm以下的GaSb层，以改善热光电（TPV）能量转换性能。由于在顶部和底部银电极之间的GaSb层内部增强的电磁场对电磁场的干扰作用，超薄超薄膜电池结构的模拟光谱特性在带隙上方显示出高吸收峰，而亚带隙吸收低至几个百分比是由于金属的高反射率。与自立式相比，在具有纳米光子电池结构的100nm以下GaSb层内，在带隙以上的特定频率下，吸收增强将近20倍。此外，MoO _x的薄层在实际中考虑将电荷收集到超膜细胞结构中作为空穴传输层。通过严格的光电分析，同时考虑了辐射和非辐射复合（Shockley-Read-Hall和Auger），预计纳米光子电池将实现22.8％的TPV效率和0.62 W / cm ^2的输出功率在1500 K时使用黑色发射器，这是由于频谱内增强了带内吸收和较低的子带隙吸收。使用理想的选择性发射器，可以通过消除亚带隙光子将效率进一步提高到28％。虽然选择性发射器在实践中仍然会遇到理想的光谱发射率和高温稳定性方面的挑战，但所提出的波长选择性纳米光子超薄膜电池可能是实现高效和低成本TPV能量转换的可行途径。