I-Corps: Solution-Processed, High-Quality Indium Tin Oxide (ITO) Films for Perovskite-Based Tandem Solar Cells

这个I-Corps项目的更广泛的影响/商业潜力是开发新的太阳能电池。轻巧灵活的太阳能电池板因其高功率输出以及在给定空间内易于运输和安装而具有吸引力。目前，市场上这种太阳能电池板的效率只有15%。该技术的目标是提供一种轻质太阳能电池板，具有高功率输出和长寿命，还可以降低电力的运行成本或产生多余的电力。该项目将探索住宅、农业和其他用户的应用。这个I-Corps项目的基础是开发一种溶液处理的高质量透明电极，用于钙钛矿基串联太阳能电池。在钙钛矿基串联太阳能电池中，透明的氧化铟锡（ITO）薄膜被用作顶部和底部子电池之间的顶部接触层和/或互连层。为了实现低成本的钙钛矿太阳能电池板的制造，通过在环境环境中进行卷对卷印刷，室温溶液处理的ITO是可取的。然而，对于常用的热板退火，ITO薄膜要经受长时间的高温，一次长达几个小时，才能获得高质量的薄膜。由于热板同时加热所有堆叠层，柔性衬底和钙钛矿吸收层可能因为有限的耐温性而损坏。该技术利用光子辐照实现了透明ITO薄膜的快速和分层退火，而不会破坏底层的堆叠层。与热板加热不同的是，每一层通过热传导共享相同的温度，光子处理可以通过光子吸收选择性地向特定层提供能量。通过快速和特定层的光子退火实现高质量溶液处理ITO的能力，为通过高速卷对卷印刷大规模制造钙钛矿基串联太阳能电池铺平了道路。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this I-Corps project is the development of new solar cells. Lightweight and flexible solar panels are attractive because of high power output, and easy transportation and installation for a given space. Currently, such solar panels on the market offer efficiencies of only 15%. The goal of the proposed technology is to provide a light-weight solar panel with high power output and long lifespan that also may reduce operational cost in electricity or generate excess electricity. This project will explore applications for residential, agricultural, and other users. This I-Corps project is based on the development of a solution-processed, high-quality transparent electrode for perovskite-based tandem solar cells. In perovskite-based tandem solar cells, transparent indium tin oxide (ITO) thin films are employed to serve as the top contact and/or interconnecting layer between top and bottom sub-cells. To realize low-cost fabrication of perovskite solar panels through roll-to-roll printing in an ambient environment, room-temperature solution-processed ITO is desirable. However, with commonly used hotplate annealing, ITO thin films are subjected to high temperatures for long durations, up to several hours at a time, to attain high-quality film. Since a hotplate heats all stacking layers simultaneously, the flexible substrates and perovskite absorber layer may be damaged because of the limited temperature resistance. The proposed technology uses photonic irradiation to achieve rapid and layer-specific annealing for transparent ITO film without damaging the underlying stacking layers. Unlike hotplate heating in which each layer shares the same temperature via thermal conduction, photonic treatment may selectively supply energy to a specific layer through photon absorption. The capability to achieve high-quality solution-processed ITO enabled by rapid and layer-specific photonic annealing paves the way for large-volume manufacturing of perovskite-based tandem solar cells by high-speed roll-to-roll printing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.