Hydrophilic or Hydrophobic? Spontaneous Chemical Capping with Bis(trifluoromethanesulfonyl)imide-Based Additive for Photoabsorbers in Perovskite Solar Cells
Naoyuki Nishimura, Ryuzi Katoh, Hiroyuki Kanda, Takurou N. Murakami
{"title":"Hydrophilic or Hydrophobic? Spontaneous Chemical Capping with Bis(trifluoromethanesulfonyl)imide-Based Additive for Photoabsorbers in Perovskite Solar Cells","authors":"Naoyuki Nishimura, Ryuzi Katoh, Hiroyuki Kanda, Takurou N. Murakami","doi":"10.1002/solr.202500433","DOIUrl":null,"url":null,"abstract":"<p>Salts based on <i>bis</i>(trifluoromethanesulfonyl)imide (TFSI) have been developed as additives for photoabsorbers in perovskite solar cells (PSCs) to enhance their photovoltaic (PV) performance. However, the effects of their TFSI anions have remained elusive. Herein, a novel methylammonium <i>bis</i>(trifluoromethanesulfonyl)imide (MA-TFSI) additive, comprising MA cations that are removed from the perovskite layer during heating, is verified. This is the first implementation of alkyl-primary-ammonium-based TFSI additives for perovskite layers. MA-TFSI addition exhibited unique chemical capping effects; the TFSI moieties were spontaneously coated on the outer surface of the perovskite and on the crystal grains during deposition, leading to the prevention of defect formation in the perovskite layer. Notably, the TFSI-capped perovskite surface displays high wettability to water droplets yet improved PV performance stability against humidity, contradicting the school of thought in the PSC research field. Parameter-differentiated contact angle (PDCA) measurements suggest that the high wettability of water droplets is attributed to the active hydrogen bonds derived from the TFSI capping. Meanwhile, the improved stability against humidity is attributable to the low dispersion energy of the CF<sub>3</sub> moiety in the TFSI capping on the crystal grains. The presented deviation from the prevailing viewpoint will lead to the advancement of materials science.</p>","PeriodicalId":230,"journal":{"name":"Solar RRL","volume":"9 19","pages":""},"PeriodicalIF":6.0000,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/solr.202500433","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Solar RRL","FirstCategoryId":"5","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/solr.202500433","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
Abstract
Salts based on bis(trifluoromethanesulfonyl)imide (TFSI) have been developed as additives for photoabsorbers in perovskite solar cells (PSCs) to enhance their photovoltaic (PV) performance. However, the effects of their TFSI anions have remained elusive. Herein, a novel methylammonium bis(trifluoromethanesulfonyl)imide (MA-TFSI) additive, comprising MA cations that are removed from the perovskite layer during heating, is verified. This is the first implementation of alkyl-primary-ammonium-based TFSI additives for perovskite layers. MA-TFSI addition exhibited unique chemical capping effects; the TFSI moieties were spontaneously coated on the outer surface of the perovskite and on the crystal grains during deposition, leading to the prevention of defect formation in the perovskite layer. Notably, the TFSI-capped perovskite surface displays high wettability to water droplets yet improved PV performance stability against humidity, contradicting the school of thought in the PSC research field. Parameter-differentiated contact angle (PDCA) measurements suggest that the high wettability of water droplets is attributed to the active hydrogen bonds derived from the TFSI capping. Meanwhile, the improved stability against humidity is attributable to the low dispersion energy of the CF3 moiety in the TFSI capping on the crystal grains. The presented deviation from the prevailing viewpoint will lead to the advancement of materials science.
Solar RRLPhysics and Astronomy-Atomic and Molecular Physics, and Optics
CiteScore
12.10
自引率
6.30%
发文量
460
期刊介绍:
Solar RRL, formerly known as Rapid Research Letters, has evolved to embrace a broader and more encompassing format. We publish Research Articles and Reviews covering all facets of solar energy conversion. This includes, but is not limited to, photovoltaics and solar cells (both established and emerging systems), as well as the development, characterization, and optimization of materials and devices. Additionally, we cover topics such as photovoltaic modules and systems, their installation and deployment, photocatalysis, solar fuels, photothermal and photoelectrochemical solar energy conversion, energy distribution, grid issues, and other relevant aspects. Join us in exploring the latest advancements in solar energy conversion research.