Abstract To design a nano-gap thermophotovoltaic device with selectively enhanced radiative transfer above the cell’s bandgap, this work theoretically investigated the near-field radiative transfer from a plasmonic Drude emitter to a nanostructured GaSb absorber, with a finite-thickness surface layer of nanowire or nanohole arrays, across a 200 nm vacuum gap. The Fourier Modal method (FMM) is used to rigorously characterize the radiative transfer involving diffractive periodic structures. The results showed that the added nanostructure, especially nanowires, effectively and selectively enhanced the near-field radiative transfer above the bandgap, with a maximum of three times the spectral radiative heat flux when compared to the unstructured GaSb case. By considering periodic structures in two dimensions, this work revealed the difference between the nanowire and nanohole absorbers in manipulating of the radiative heat flux, showing that the nanowire array offers largely enhanced radiative heat transfer compared with the nanohole arrays with similar geometric parameters, which cannot be quantitatively characterized by effective medium theories even though the structural size is much smaller than the studied wavelength. The results proved that nanohole and nanowire structures can be used to significantly enhance the power and efficiency of a nano-gap thermophotovoltaic device, for which the equivalent of anti-reflection structures of the semiconductor cells have seldom been studied.

中文翻译：

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用于热光伏的纳米孔和纳米线周期性阵列选择性增强等离子体发射器和 GaSb 之间的近场辐射传输

摘要 为了设计一种在电池带隙上方选择性增强辐射转移的纳米间隙热光伏器件，本工作从理论上研究了从等离子体 Drude 发射体到纳米结构 GaSb 吸收体的近场辐射转移，具有有限厚度的纳米线或纳米线表面层。纳米孔阵列，跨越 200 nm 真空间隙。傅里叶模态方法 (FMM) 用于严格表征涉及衍射周期结构的辐射传输。结果表明，添加的纳米结构，尤其是纳米线，有效且选择性地增强了带隙上方的近场辐射传递，与非结构化 GaSb 情况相比，光谱辐射热通量最大提高了三倍。通过考虑二维周期结构，这项工作揭示了纳米线和纳米孔吸收器在操纵辐射热通量方面的差异，表明与具有相似几何参数的纳米孔阵列相比，纳米线阵列提供了大大增强的辐射传热，即使有效介质理论也无法对其进行定量表征尽管结构尺寸远小于研究的波长。结果证明，纳米孔和纳米线结构可以显着提高纳米间隙热光伏器件的功率和效率，为此很少研究半导体电池的等效抗反射结构。表明与具有相似几何参数的纳米孔阵列相比，纳米线阵列提供了大大增强的辐射传热，即使结构尺寸远小于研究的波长，也无法通过有效介质理论进行定量表征。结果证明，纳米孔和纳米线结构可以显着提高纳米间隙热光伏器件的功率和效率，为此很少研究半导体电池的等效抗反射结构。表明与具有相似几何参数的纳米孔阵列相比，纳米线阵列提供了大大增强的辐射传热，即使结构尺寸远小于研究的波长，也无法通过有效介质理论进行定量表征。结果证明，纳米孔和纳米线结构可以显着提高纳米间隙热光伏器件的功率和效率，为此很少研究半导体电池的等效抗反射结构。