Nanowires for Energy

该提案旨在开发基于III-V半导体纳米线的新型太阳能电池或光伏（PV）技术。迄今为止，最高的太阳能电池效率是使用III-V半导体材料，如砷化镓，在集中的阳光下，研究级太阳能电池的效率超过40%。这些器件在多结器件结构中采用高度完美的半导体薄膜，该结构由电串联的子电池组成。然而，由于需要使用类似晶格的材料来避免在薄膜中产生会降低效率的缺陷，这些电池没有得到优化。此外，由于使用锗等材料，现有的薄膜技术非常昂贵。为了克服这些限制，本提案提出了一种由纳米线组成的双结电池，该电池位于相对便宜的衬底（如硅）上。纳米线的主要优点是可以更自由地组合不同晶体结构的材料，以优化太阳能电池的效率。因此，基于纳米线的太阳能电池应该具有与商业薄膜电池相当的最佳效率（bbb40 %），而前者将通过使用更便宜的衬底来显着降低成本。我们最近的理论研究表明，当纳米线直径、长度和间距优化时，纳米线光伏器件的效率最高。因此，本提案的主要焦点将是有序纳米线阵列的发展。从科学上讲，这一建议将为基于纳米线的器件的设计提供关键方面。由该提案生产的原理验证设备将催化纳米结构III-V/Si太阳能电池领域的全球显着增长，加拿大将成为该领域的主要竞争者。

This proposal is aimed at developing a new solar cell or photovoltaic (PV) technology based on III-V semiconductor nanowires. The highest solar cell efficiencies achieved thus far use III-V semiconductor materials such as gallium arsenide, where research-grade solar cells have exceeded 40% efficiency under concentrated sunlight. These devices employ highly perfect semiconductor thin films in a multi-junction device structure, which consists of sub-cells connected electrically in series. However, these cells are not optimized due to the need to use materials of similar crystal lattice to avoid the generation of defects in the films that would otherwise reduce efficiency. Furthermore, the existing thin film technology is prohibitively expensive due to the materials used such as germanium. To overcome these limitations, this proposal proposes a two-junction cell comprised of nanowires on relatively inexpensive substrates such as silicon. The main advantage of nanowires is the greater freedom to combine materials of different crystal structure to optimize solar cell efficiency. As a result, a nanowire-based solar cell should have optimum efficiency that is comparable to that of commercial thin film cells (>40%), while the former would significantly reduce cost by using cheaper substrates. The efficiency of a nanowire PV device is greatest when the nanowire diameter, length, and spacing are optimized as shown by our recent theoretical work. Therefore, the main focus of this proposal will be the development of ordered nanowire arrays. Scientifically, this proposal will provide key aspects in the design of nanowire-based devices. The proof-of-principle devices produced by this proposal will catalyze a significant worldwide increase within the area of nanostructured III-V/Si solar cells, an area where Canada will then be a leading contender.