Title: The critical role of substrates in mitigating the power-efficiency trade-off in near-field thermophotovoltaics Show Chinese title

Title: 近场热光伏中基底在缓解功率-效率权衡中的关键作用

Abstract: Near-field thermophotovoltaic systems can achieve ultra-high power densities, however, this often comes at the cost of reduced efficiency. We show that this power-efficiency trade-off can be mitigated through substrate engineering. We exploit gradient-based optimization and show that thin lossless metallic films with plasma frequencies resonantly matched to the plasmonic emitter can yield high power and spectral efficiency by spectrally enhancing and confining radiative heat transfer to a narrow spectral range just above the photovoltaic bandgap. Compared to noble metals and air-bridged structures, designs deriving from such optimization yield more than an order-of-magnitude increase in radiative power density while maintaining high efficiency. Our results highlight the critical role of the substrate and the potential of substrate optimization for overcoming fundamental limitations of near-field thermophotovoltaic systems. Show Chinese abstract

Abstract: 近场热光伏系统可以实现超高的功率密度，然而，这通常会以效率降低为代价。 我们表明，通过衬底工程可以缓解这种功率-效率权衡。 我们利用基于梯度的优化，并表明具有等离子体频率与等离子体发射器共振匹配的薄无损耗金属薄膜可以通过光谱增强和限制辐射热传递到光伏带隙上方的窄光谱范围，从而实现高功率和光谱效率。 与贵金属和空气桥结构相比，由此优化得到的设计在保持高效率的同时，辐射功率密度提高了超过一个数量级。 我们的结果突出了衬底的关键作用，以及衬底优化在克服近场热光伏系统基本限制方面的潜力。