Tokyo Chemical Industry (TCI), a global supplier of laboratory chemicals and specialty materials, is offering OA-TFSI (n-Octylammonium Bis(trifluoromethanesulfonyl)imide), an additive for the Spiro-OMeTAD hole transport layer in perovskite solar cells that provides both doping and passivation.
TCI explains that when OA-TFSI is added during the formation of the Spiro-OMeTAD hole transport layer, its two ions play different roles: the TFSI anion acts as a dopant for the hole transport material, while the n-octylammonium cation passivates the underlying perovskite layer. Compared to LiTFSI, the lithium salt commonly used as a Spiro-OMeTAD additive, OA-TFSI improves both the power conversion efficiency (PCE) and the stability of the device.
In the process shown above, a chlorobenzene solution of 70 mM Spiro-OMeTAD, 12 mM OA-TFSI and 36 mM tert-butylpyridine is spin-coated onto a FAPbI₃ perovskite layer (on TiO₂ and FTO) to form the hole transport layer. The approach is based on work by Prof. Nishimura, Prof. Murakami and colleagues, who described aliphatic primary ammonium TFSI room-temperature ionic liquids as highly functional HTM additives in a 2023 ACS Applied Materials & Interfaces paper, and more recently studied the coordination of tert-butylpyridine to alkylammoniums in perovskites (J. Mater. Chem. A, 2026).
TCI offers the material as product O0750, alongside the related Spiro-OMeTAD (T3672) and LiTFSI (B2542). A product brochure (PDF) is available here.
Tokyo Chemical Industry offers a wide range of materials for the perovskite industry, including perovskite precursors, high-performance hole collecting materials, TM-DHP additives, Phenylethylamine Hydroiodides materials, Zinc compounds, PACz as p-type SAM forming agents, PDINN materials, SMORI passivation materials, PANDI as an n-type SAM forming agents, Spiro-OMeTAD hole transporting materials, and more. We published an interview with TCI in 2022 to discuss their perovskite materials and views on the industry and market.
This was a sponsored post by TCI