SBIR Phase I: Low-Cost, Nanoepitaxial Lateral Over-Growth for III-V Metamorphic Solar Cells

该小型企业创新研究(SBIR)第一阶段项目旨在大幅降低用于地面集中器光伏(CPV)太阳能发电的多结太阳能电池的成本。目前最受欢迎的太阳能电池类型是倒置变质多结(IMM)，它提供了最高的转换效率。然而，该单元最厚和最昂贵的单一区域是缓冲层，它提供子单元之间的晶格常数的过渡，但对当前的生成没有贡献。另外，生长在缓冲层上的变质亚细胞受到源于缓冲层的缺陷的不利影响。在这个项目中，缓冲层将被纳米颗粒层取代，这将允许变质亚细胞在较短的距离内形成，几乎没有缺陷。该项目的更广泛的商业影响将是提供一种制造IMM太阳能电池的新技术的潜力，从而显著降低成本。IMM太阳能电池是陆地CPV太阳能发电机的关键部件，占其成本的很大一部分。因此，IMM电池成本的降低应该会降低太阳能发电的成本。这种方法有望使IMM细胞的生长时间减少50%，材料清单(BOM)减少30%。

This Small Business Innovation Research (SBIR) Phase I project aims to substantially reduce the cost of multijunction solar cells for terrestrial concentrator photovoltaic (CPV) solar power generation. The presently favored type of solar cell for CPV applications is the inverted metamorphic multijunction (IMM), which offers the highest conversion efficiency. However, the thickest and most costly single region of this cell is the buffer layer, which provides a transition in the lattice constant between subcells, but does not contribute to current generation. Plus, the metamorphic subcell, which is grown on the buffer layer, is adversely affected by defects which originate in the buffer layer. In this project, the buffer layer will be replaced with a nanopatterned layer, which will allow the metamorphic subcell to form in a short distance with few defects. The broader/commercial impact of this project will be the potential to provide a new technique to fabricate IMM solar cells, allowing a significant cost reduction. IMM solar cells are a key component of terrestrial CPV solar power generators and account for a substantial fraction of their cost. A reduction in the cost of IMM cells should therefore lower the cost of solar-generated electricity. This approach is expected to achieve a 50% reduction in growth time and a 30% reduction in the bill of materials (BOM) of IMM cells.