Thermophotovoltaic (TPV) cells generate electricity by converting infrared radiation emitted by a hot thermal source. Air-bridge TPVs have demonstrated enhanced power conversion efficiencies by recuperating a large amount of power carried by below-band-gap (out-of-band) photons. Here, we demonstrate single-junction InGaAs(P) air-bridge TPVs that exhibit up to 44% efficiency under 1,435°C blackbody illumination. The air-bridge design leads to near-unity reflectance (97%–99%) of out-of-band photons for ternary and quaternary TPVs whose band gaps range from 0.74 to 1.1 eV. These results suggest the applicability of the air-bridge cells to a range of semiconductor systems suitable for electricity generation from thermal sources found in both consumer and industrial applications, including thermal batteries.

热光伏 (TPV) 电池通过转换热热源发出的红外辐射来发电。空桥 TPV 通过回收带隙以下（带外）光子携带的大量功率，展示了增强的功率转换效率。在这里，我们展示了单结 InGaAs(P) 空气桥 TPV，其在 1,435°C 黑体照明下表现出高达 44% 的效率。对于带隙范围为 0.74 至 1.1 eV 的三元和四元 TPV，空气桥设计可实现近乎一致的带外光子反射率 (97%–99%)。这些结果表明，空气桥电池适用于一系列适合利用消费和工业应用中的热源（包括热电池）发电的半导体系统。