Interface Engineering for Terawatt Scale Deployment of Perovskite-on-Silicon Tandem Solar Cells

太瓦(TW)可再生能源的部署对于世界实现净零排放至关重要。太阳能发电是最有前景的可再生能源发电技术之一，拥有最大的可利用资源。为了将太阳能发电量提高到太瓦的水平，我们必须加快开发能够实现更高效率的新技术。目前，占主导地位的硅技术已接近其实际效率极限。为了获得更高的性能，必须在所谓的串联架构中采用其他半导体吸收体：两个或更多个光吸收体相互集成在一起，以更好地利用高能可见光光子，减少热化损失，并将更高比例的太阳能转换为电能。在这些新型吸波材料中，有机-无机混合金属卤化物钙钛矿半导体最近取得了前所未有的进展，是最有希望集成到串联器件中的技术。将钙钛矿与硅集成以制造高效率电池已经取得了重大进展，但到目前为止，努力几乎无处不在地使用高端硅异质结后电池，这并不代表主流的大规模生产硅光伏技术。在这个项目中，我们将致力于基于最低成本的“PERC”和“Topcon”硅电池的钙钛矿硅串联太阳能电池的开发。我们的目标是提供一种新型串联技术，由于放弃使用稀有材料，并采用完全可扩展的制造方法，对硅和钙钛矿电池都具有扩大到TW水平的潜力。使庞大的硅电池生产装机容量能够“升级”到钙钛矿级联技术，这将加速钙钛矿硅芯片的部署，而这在目前的设计中尚不可能实现。最重要的是，转向可扩展的Tandem将在每平方米能量捕获方面产生高达45%的阶跃变化(从24%到35%abs)，而额外成本微乎其微。由于光伏制造的二氧化碳排放有一半来自硅生产，因此更高的能效极大地减少了单位发电量的碳足迹，有可能降至迄今所有发电技术的最低水平。

Terawatt (TW) deployment of renewable energy is critical for the world to achieve net-zero emissions. Solar power is one of the most promising technologies for renewable electricity generation and has the largest available resource for exploitation. To boost solar electricity to TW levels, we must accelerate the development of new technologies enabling ever higher efficiencies. At present, the dominant silicon technology is close to reaching its practical efficiency limit. For higher performance to be unlocked, other semiconductor absorbers must be adopted in what is known as a tandem architecture: where two or more light absorbers are integrated on top of each other to make better use of high energy visible photons, reduce thermalisation losses and convert a higher fraction of the solar energy into electrical energy. Among such new absorbers, mixed organic-inorganic metal halide perovskite semiconductors have recently witnessed unprecedented progress and are the most promising technology to integrate into a tandem device. Significant advances have already been made integrating perovskites with silicon to make high efficiency tandems, but efforts so far have almost ubiquitously employed high-end silicon heterojunction rear cells, which do not represent the main-stream mass-produced Si PV technology. In this project, we will tackle the development of perovskite-on-silicon tandem solar cells based on the lowest cost "PERC" and "TOPCon" silicon cells. Our goal is to deliver a novel tandem technology with the potential to scale up to TW levels, due to moving away from the use of rare materials, and employing fully-scalable manufacturing methodologies, for both the silicon and perovskite cells. Enabling the vast installed capacity for silicon cell production to "upgrade" to perovskite tandem technology will accelerate deployment of perovskite-on-silicon tandems in a way that it is not yet possible with current designs. Most importantly, a shift towards scalable tandems will produce a step change in energy capture per metre square as high as 45%rel (from 24% to 35%abs), at a marginal extra cost. Because half the CO2 emissions of PV manufacturing come from silicon production, tandem higher efficiencies greatly reduce the carbon footprint per unit energy generated, potentially to the lowest level of any electricity generating technology to date.