Thermophotovoltaic (TPV) devices, which convert infrared thermal radiation from a hot emitter into electricity, hold great promise for applications in energy storage and waste heat recovery. While recent advancements have developed TPV devices with high efficiency, much less attention has been focused on improving the power density. Current TPV methods face challenges in significantly boosting power density without an emitter at very high temperatures (> 2000 °C) or using complex, costly architectures such as near-field TPV. Here we present the first experimental demonstration of a novel far-field TPV concept called “zero-vacuum-gap TPV” that eliminates the vacuum or gas-filled gap in conventional designs. By incorporating a high-index, infrared-transparent, and thermally insulating fused quartz spacer, we achieved a twofold increase in power density compared to the far-field counterpart under identical conditions. Notably, in our experiment, the zero-vacuum-gap far-field design transforms an less-optimized, low-power-density far-field device into one with one of the highest power density reported at moderate temperatures (700-1100 °C). Moreover, our measurements using graphite emitter surpasses the blackbody limit for gap-integrated far-field devices and matches the performance of near-field TPV with an ultrathin 200-nm gap. Our findings suggest that zero-vacuum-gap TPV offers potential for cost-effective, scalable manufacturing using current technologies. Additionally, our modelling predicts that further power enhancements over one order of magnitude are possible with other spacer materials.

中文翻译：

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提高零真空间隙热光伏器件的功率密度


热光伏 （TPV） 器件将来自热发射器的红外热辐射转化为电能，在储能和余热回收方面具有很大的前景。虽然最近的进展开发了高效率的 TPV 器件，但很少有人关注提高功率密度。当前的 TPV 方法面临着在极高温度 （> 2000 °C） 下无发射器的情况下显著提高功率密度或使用复杂、昂贵的架构（如近场 TPV）的挑战。在这里，我们首次展示了一种称为“零真空间隙 TPV”的新型远场 TPV 概念的实验演示，该概念消除了传统设计中的真空或充气间隙。通过采用高折射率、红外透明和隔热的熔融石英垫片，与相同条件下的远场垫片相比，我们的功率密度提高了两倍。值得注意的是，在我们的实验中，零真空间隙远场设计将不太优化的低功率密度远场器件转变为在中等温度 （700-1100 °C） 下具有最高功率密度的远场器件。此外，我们使用石墨发射器的测量超过了间隙集成远场器件的黑体限制，并与具有 200 nm 超薄间隙的近场 TPV 的性能相匹配。我们的研究结果表明，零真空间隙 TPV 为使用当前技术实现经济高效、可扩展的制造提供了潜力。此外，我们的建模预测，使用其他垫片材料可以在一个数量级上进一步提高功率。