Singlet Fission Photon Multipliers - Adding Efficiency to Silicon Solar Cells

太阳能可以为全球能源供应做出重大贡献，但要使这种可再生能源产生重大影响，它需要与传统能源在成本上竞争。硅太阳能电池是现有的光伏技术，并且在过去5-8年中受益于制造成本的大幅降低。现在，模块成本不再是安装系统成本的最大组成部分，进一步降低每安装瓦的成本需要提高电池效率。然而，单结电池，如硅是从根本上限制的事实，超过半导体带隙能量的太阳能光谱的能量作为热量损失。我们的目标是开发一种简单的活性膜，可以应用到硅（或任何其他）太阳能电池的前表面，将增加电池效率高达4%（例如，从20%到24%）。我们将通过从太阳光谱中捕获高能光子并将其转换为两个可以在太阳能电池中吸收而不会损失热量的低能光子来实现这一点。这将使用在某些有机材料中发生的单重态激子裂变过程来实现，将光子吸收产生的自旋0单重态转换为两个自旋1三重态。我们最近已经证明，有可能将这些非发射三重态转移到无机半导体纳米颗粒上，然后可以有效地发射光子，这些光子可以被底层太阳能电池吸收。在这个项目中，我们将优化，设计和演示基于上述方法的光子倍增器薄膜，为硅太阳能电池提供低成本的效率提高，其可以在不重新设计电池的电结构的情况下实现。

Solar energy can make a major contribution to global energy supply, but for this renewable energy source to make a major impact it will need to compete on cost with conventional sources of energy. Silicon solar cells are the incumbent photovoltaic technology, and have benefited from huge reductions in manufacturing costs over the last 5-8 years. Now that the module cost is no longer the largest component of the installed system cost, further reductions in the cost per installed Watt require increases in the cell efficiency. However, single-junction cells such as silicon are fundamentally limited by the fact that the energy of the solar spectrum in excess of the semiconductor bandgap energy is lost as heat.We aim to develop a simple active film that can be applied to the front surface of a silicon (or any other) solar cell that will increase the cell efficiency by up to 4% (e.g. from 20% to 24%). We will do this by capturing the high-energy photons from the solar spectrum and converting them to two lower-energy photons that can be absorbed in the solar cell without energy losses to heat. This will be achieved using the process of singlet exciton fission which occurs in certain organic materials, converting the spin-0 singlet state produced by photon absorption into two spin-1 triplet states. We have very recently demonstrated that it is possible to transfer these non-emissive triplet states onto inorganic semiconductor nanoparticles, which can then efficiently emit photons that could be absorbed by an underlying solar cell.In this project, we will optimise, engineer and demonstrate photon multiplier films based on the approach described above, providing a low-cost efficiency enhancement for silicon solar cells that can be implemented without re-engineering of the electrical structure of the cell.