Harwell Jonathon, Samuel Ifor D W
School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS, United Kingdom.
ACS Appl Nano Mater. 2023 Aug 16;6(16):14940-14947. doi: 10.1021/acsanm.3c02493. eCollection 2023 Aug 25.
Back-contact perovskite solar cells are of great interest because they could achieve higher performance than conventional designs while also eliminating the need for transparent conductors. Current research in this field has focused on making electrode structures with reduced widths to collect charges more efficiently, but current lift-off-based fabrication techniques have struggled to achieve electrode widths smaller than 1000 nm and are difficult to implement on large areas. We demonstrate nanoimprint lithography in an etch-down procedure as a simple and easily scalable method to produce honeycomb-shaped, quasi-interdigitated electrode structures with widths as small as 230 nm. We then use electrodeposition to selectively deposit conformal coatings of a range of different hole-selective layers and explore how the efficiency of back-contact perovskite solar cells changes as the feature sizes are pushed into the nanoscale. We find that the efficiency of the resulting devices remains almost unchanged as the electrode width is varied from 230 to 2000 nm, which differs from reported device simulations. Our results suggest that reducing recombination and improving the quality of the charge transport layers, rather than reducing the minimum feature size, are likely to be the best pathway to maximizing the performance of back-contact perovskite solar cells.
背接触钙钛矿太阳能电池备受关注，因为它们不仅能够实现比传统设计更高的性能，还无需透明导体。该领域目前的研究重点是制造宽度更小的电极结构，以更有效地收集电荷，但目前基于剥离的制造技术难以实现宽度小于1000纳米的电极，并且难以在大面积上实施。我们展示了在蚀刻过程中使用纳米压印光刻技术，这是一种简单且易于扩展的方法，可制造宽度小至230纳米的蜂窝状准交错电极结构。然后，我们使用电沉积选择性地沉积一系列不同空穴选择层的保形涂层，并探究随着特征尺寸缩小到纳米级，背接触钙钛矿太阳能电池的效率如何变化。我们发现，当电极宽度从230纳米变化到2000纳米时，所得器件的效率几乎保持不变，这与报道的器件模拟结果不同。我们的结果表明，减少复合并提高电荷传输层的质量，而非减小最小特征尺寸，可能是最大化背接触钙钛矿太阳能电池性能的最佳途径。
