Energy Resilient Manufacturing 2: Enabling Practical TPVs for Waste Heat Recovery

直接将热转化为电的有效、实用和经济的方法是一个非常吸引人的概念。原则上，热光伏（TPV）电池可以构成各种系统的关键组成部分，用于从不同类型的热源发电，包括燃烧过程、集中阳光、废热和放射性同位素。这为技术采用开辟了多种可能性，因此可以设想TPV系统用于从小型电源到替代电池到大规模热电联产的各种应用。然而，现有的TPV电池是基于GaSb的，并且光谱匹配的热源温度为~1800℃，这限制了它们的实际实施和广泛采用。带隙为0.53 eV的GaInAsSb TPV电池表现出优异的性能，其内部量子效率接近95%。但是，目前这些都是在GaSb基板上的晶格匹配，除了在专业的高价值或空间应用中，它们对于实际实施来说过于昂贵。在更大尺寸GaAs衬底上的TPV开发将通过更便宜的TPV电池的批量生产实现有效的技术吸收。因此，有必要将GaInAsSb单元结构转移到GaAs。在这个项目中，我们将以英国现有的世界级III-V级半导体材料专业知识为基础，在廉价的GaAs衬底上制造新型低带隙InGaAsSb TPV阵列，能够从工业过程中常见的500-1500℃范围内的热废热源高效发电。这些单片阵列将与我们在皮尔金顿和MPIUK（塔塔钢铁）的行业合作伙伴一起进行现场验证。该项目将展示制造大面积TPV阵列的下一步，这对TPV热回收的商业可行性至关重要，并将使其在玻璃、钢铁和水泥制造、石油/天然气和能源生产等高能耗行业得到广泛应用。

An efficient, practical and cost-effective means for directly converting heat into electricity is a very appealing concept. In principle, thermo-photovoltaic (TPV) cells could form the critical component of various systems for generating electricity from different types of heat sources including combustion processes, concentrated sunlight, waste process heat, and radio isotopes. This opens up a wide variety of possibilities for technology uptake and so TPV systems can be envisaged for use in applications ranging from small power supplies to replace batteries, to large scale co-generation of electricity. However, existing TPV cells are based on GaSb and are spectrally matched to heat sources at temperatures of ~1800 oC which limits their practical implementation and widespread uptake. GaInAsSb TPV cells with bandgap 0.53 eV have exhibited excellent performance with internal quantum efficiency near 95%. But, currently these are lattice-matched on GaSb substrates making them too expensive for practical implementation except in specialist high value or space applications. TPV development on larger format GaAs substrates will enable effective technology uptake through cheaper volume manufacturing of TPV cells. Consequently, there is a need to transfer the GaInAsSb cell architecture to GaAs.In this project we shall build on existing UK based world class III-V semiconductor materials expertise to fabricate novel low bandgap InGaAsSb TPV arrays on inexpensive GaAs substrates, capable of efficient electricity generation from thermal waste heat sources in the range 500-1500 oC commonly encountered in industrial processes. These monolithic arrays will be validated on-site together with our industry partners at Pilkington and MPIUK (Tata steel). The project will demonstrate the next step towards fabrication of large area TPV arrays essential for the commercial viability of TPV heat recovery, and will enable their widespread implementation in a wide range of high energy consumption industries such as glass, steel and cement manufacture, oil/gas and energy generation.