Recent advancements in perovskite solar cell technology have emerged from research led by Linfeng Ye at the State Key Laboratory of Solidification Processing in the Center for Nano Energy Materials at Northwestern Polytechnical University. Published in Nature Communications, this study introduces a novel approach to enhancing the stability and efficiency of perovskite solar cells (PSCs) by utilizing a metal-free spiro-OMeTAD as a hole-transport layer (HTL).
Traditionally, lithium salt-doped spiro-OMeTAD has been the go-to material for HTLs in PSCs, but its commercialization has been hindered by significant stability issues stemming from lithium ion migration and its hygroscopic nature. Ye and his team have tackled these challenges by developing an HTL derived from superoxide radicals (•O2 −). This innovative material allows for a more straightforward pre-oxidation process of spiro-OMeTAD, eliminating the need for the conventional and cumbersome oxidation treatment in air.
The research highlights the use of variant-valence Eu(TFSI)2 salts, which generate the superoxide radicals necessary for this process. As a result, the modified spiro-OMeTAD exhibits dramatically improved electrical conductivity and work function. The findings are compelling, demonstrating that PSCs utilizing this new HTL achieved efficiencies of 25.45% for small active areas and 20.76% for larger modules measuring 6 × 6 cm².
These advancements are particularly significant for the solar energy sector. The enhanced environmental stability of these PSCs is noteworthy; the devices maintained over 90% of their initial efficiency after 1000 hours of operation under maximum power conditions and retained their performance even after undergoing 80 light-thermal cycles designed to simulate low Earth orbit conditions. This level of durability opens up new opportunities for the deployment of perovskite solar cells in various environments, including space applications and regions with extreme weather conditions.
Ye emphasizes the implications of their work, stating, “This research indicates the potential of developing metal-free spiro-OMeTAD for low-cost and shortened processing of perovskite photovoltaics.” As the industry seeks more sustainable and efficient solar technologies, this breakthrough could pave the way for more commercially viable perovskite solar cells, potentially transforming the landscape of renewable energy.
In summary, the research from Ye and his team represents a significant leap forward in the quest for stable and efficient perovskite solar cells, positioning the technology for broader commercial adoption and offering new avenues for innovation in the renewable energy sector.
