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陆地聚光光伏（CPV）太阳能发电的多结太阳能电池的成本。目前，CPV应用中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，该电池的最厚和最昂贵的单个区域是缓冲层，其提供子电池之间的晶格常数的过渡，但不有助于电流生成。 另外，生长在缓冲层上的变质子电池受到源自缓冲层的缺陷的不利影响。在这个项目中，缓冲层将被纳米图案层取代，这将允许变形子电池在短距离内形成，几乎没有缺陷。 该项目的更广泛/商业影响将是提供制造IMM太阳能电池的新技术的潜力，从而显著降低成本。 IMM太阳能电池是地面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。这种方法预计将实现生长时间减少50%，IMM电池的物料清单（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.