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

一种高效、实用和成本效益高的直接将热能转化为电能的方法是一个非常有吸引力的概念。从原理上讲，热光电池可以构成各种系统的关键部件，这些系统可以利用不同类型的热源发电，包括燃烧过程、集中的阳光、废热过程和放射性同位素。这为采用技术提供了广泛的可能性，因此可以设想TPV系统可用于从小型电源到大型热电联产的各种应用。然而，现有的TPV电池是基于GASB的，并且在~1800℃的温度下与热源进行光谱匹配，这限制了它们的实际实施和广泛吸收。禁带宽度为0.53 eV的GaInAsSb TPV电池表现出优异的性能，内量子效率接近95%。但是，目前它们是在GaSb衬底上晶格匹配的，这使得它们过于昂贵，除非在专业的高价值或空间应用中，否则无法实际实施。在更大尺寸的GaAs衬底上开发TPV将通过更便宜的批量制造TPV电池来实现有效的技术吸收。因此，有必要将GaInAsSb电池架构转移到GaAs。在这个项目中，我们将基于现有的英国世界级III-V半导体材料专业知识，在廉价的GaAs衬底上制造新型的低禁带InGaAsSb TPV阵列，能够在500-1500 oC的范围内利用工业过程中常见的热余热源高效发电。这些单片阵列将与我们在皮尔金顿和MPIUK(塔塔钢铁公司)的行业合作伙伴一起在现场进行验证。该项目将展示制造对TPV热回收的商业可行性至关重要的大面积TPV阵列的下一步，并将使其能够在玻璃、钢铁和水泥制造、石油/天然气和能源发电等广泛的高耗能行业广泛实施。

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.