EAGER:TDM Solar Cells: Collaborative Research: 30%-Efficient, Stable Perovskite/Silicon Monolithic Tandem Solar Cells

【摘要】太阳能电池从太阳获取能量并发电，使我们的能源组合多样化，并将成为减少我们对化石燃料的依赖和防止不良气候变化的重要组成部分。重要的是要使太阳能电池板尽可能高效，这样才能减少获得一定电量所需的电池板数量，从而节省安装成本。串联电池由收集可见光部分的顶部电池和收集红外部分的底部电池组成，是最有希望实现更高效率的方法。每年约有92%的太阳能电池板使用硅，它是底部电池的理想材料，其效率通常为16- 21%。钙钛矿半导体对顶层电池非常有吸引力，因为它们可以调整到合适的带隙，效率高达22%。该项目的目标是展示第一个30%效率的钙钛矿/硅串联太阳能电池。技术描述该项目描述了钙钛矿专家Michael McGehee教授与硅专家Zachary Holman教授合作制造钙钛矿/硅串联太阳能电池的计划。该团队制作了一个原型双端单片器件，功率转换效率为25.3%。他们保持着这类设备的世界纪录，并且在未来两年内将效率提高到30%方面处于非常有利的地位。这一发展尤其令人兴奋，因为他们的包装钙钛矿太阳能电池已经通过了光伏行业标准的湿热和温度循环测试，并且很可能以每平方米100美元的成本制造这些电池的面板。使用ABX3材料可以将钙钛矿的带隙从1.2 eV调整到2.3 eV，其中A是甲基铵、甲脒或铯的混合物，B是锡和铅的混合物，X是溴或碘的混合物。该项目最重要的研究目标是找到这些组件的最佳组合，以制造具有1.8 eV带隙的稳定高质量半导体。该团队将彻底表征其制造的半导体，以指导优化性能的过程。该项目的其他研究目标是开发用于串联太阳能电池前部的高迁移率TCO层，通过多孔介质/金属后反射器提高硅底部电池的红外响应，同时降低其成本，并制造具有散射纹理的PDMS层，用于串联太阳能电池前部以降低反射率。该项目有潜力通过开发高效且廉价的光伏技术来改变我们未来的能源格局。该项目还将培训各种各样的学生，其成果将得到广泛传播。Holman是NSF REU站点的PI，该站点将被整合到拟议的项目中。McGehee大约每18个月做一次讲座，旨在让那些还不是科学家的人也能容易理解，并将其发布在YouTube上。这些讲座通常被各种各样的人观看超过2万次。

AbstractNontechnical DescriptionSolar cells, which harvest energy from the sun and generate electricity, are diversifying our energy portfolio and will be an important part of reducing our dependence on fossil fuels and preventing undesirable climate change. It is important to make solar panels as efficient as possible so that the number of panels needed to obtain a certain amount of power can be reduced in order to save on installation costs. Tandem cells, comprised of a top cell that harvests the visible portion of the spectrum and a bottom cell that harvests the infrared portion, are the most promising way to achieve higher efficiencies. Silicon, which is used in approximately 92% of the solar panels that are manufactured each year, is ideal for the bottom cell and typically has 16-21 % efficiency by itself. Perovskite semiconductors are highly attractive for the top cell because they can be tuned to have the right bandgap and have efficiency as high as 22%. The objective of this project is to demonstrate the first 30%-efficient perovskite/silicon tandem solar cell. Technical DescriptionThis project describes plans for a perovskite expert, Professor Michael McGehee, to partner with a silicon expert, Professor Zachary Holman, to make perovskites/silicon tandem solar cells. This team has made a prototype two-terminal monolithic device with a power conversion efficiency of 25.3 %. They hold the world record for this type of device and are in a very strong position to increase the efficiency to 30% over the next two years. This development is especially exciting because their packaged perovskite solar cells have already passed the PV industry standard damp heat and temperature cycling tests and it is likely that panels with these cells could be manufactured at a cost of $100/m2. The bandgap of perovskites can be tuned from 1.2 eV to 2.3 eV using the materials set ABX3, where A is a mixture of methylammonium, formamidinium or cesium, B is a mixture of tin and lead, and X is a mixture of bromine or iodine. The most important research goal of this project is to find the optimal combination of these components for making a stable and high-quality semiconductor with a bandgap of 1.8 eV. The team will thoroughly characterize the semiconductors it makes to guide the process of optimizing the properties. Additional research goals of this project are to develop high-mobility TCO layers for the front of the tandem solar cells, improve the infrared response of the silicon bottom cell while decreasing its cost via a porous dielectric/metal rear reflector, and fabricate PDMS layers with scattering textures to be used at the front of the tandem to reduce reflectance.This project has the potential to change our future energy landscape through the development of efficient yet inexpensive PV technologies. The project will also train a diverse pool of students and the results will be disseminated broadly. Holman is the PI of an NSF REU site into which the proposed project will be integrated. Approximately once every 18 months McGehee gives a lecture that is intended to be easy to understand even for people who are not yet scientists and posts it on YouTube. These lectures are typically viewed more than 20,000 times by a wide variety of people.