Recent advances in thermophotovoltaic (TPV) power generation have produced notable gains in efficiency, particularly at very high emitter temperatures. However, there remains substantial room for improving TPV conversion of waste, solar, and nuclear heat streams at temperatures below 1,100°C. Here, we demonstrate the concept of transmissive spectral control that enables efficient recuperation of below-bandgap photons by allowing them to transmit through the cell to be absorbed by a secondary emitter. We fabricate a semitransparent TPV cell consisting of a thin InGaAs–InP heterojunction membrane supported by an infrared-transparent heat-conducting substrate. The device absorbs less than 1% of below-bandgap radiation, resulting in a TPV efficiency of 32.5% at an emitter temperature of 1,036°C. To our knowledge, this represents an 8% absolute improvement (~33% relative) in efficiency relative to the best TPV devices at such low temperatures. By enabling near-zero photon loss, the semitransparent architecture facilitates high TPV efficiencies over a wide range of applications.

中文翻译：

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用于高效利用中温热辐射的半透明热光伏材料

热光伏 (TPV) 发电的最新进展显着提高了效率，尤其是在非常高的发射极温度下。然而，在低于 1,100°C 的温度下，仍有很大的空间可以提高废物、太阳能和核热流的 TPV 转化率。在这里，我们展示了透射光谱控制的概念，该概念通过允许带隙以下的光子传输穿过电池以被二次发射器吸收，从而实现带隙以下光子的有效恢复。我们制造了一个半透明 TPV 电池，该电池由薄的 InGaAs-InP 异质结膜组成，由红外透明导热基板支撑。该器件吸收不到 1% 的带隙以下辐射，从而在 1,036°C 的发射器温度下实现 32.5% 的 TPV 效率。据我们所知，在如此低的温度下，相对于最好的 TPV 器件，这意味着效率绝对提高了 8%（相对 33%）。通过实现接近零的光子损失，半透明架构有助于在广泛的应用中实现高 TPV 效率。