In Situ Thermal Cross-Linking of 9,9′-Spirobifluorene-Based Hole-Transporting Layer for Perovskite Solar Cells

• Published in: ACS applied materials & interfaces Vol. 16; no. 1; pp. 1206 - 1216
• Main Authors: Daskeviciute-Geguziene, Sarune, Truong, Minh Anh, Rakstys, Kasparas, Daskeviciene, Maryte, Hashimoto, Ruito, Murdey, Richard, Yamada, Takumi, Kanemitsu, Yoshihiko, Jankauskas, Vygintas, Wakamiya, Atsushi, Getautis, Vytautas
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 10.01.2024
• Subjects: Organic Electronic Devices; temperature; perovskite solar cell; hole-transporting layer; cross-linking; spirobifluorene
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.3c13950

A novel 9,9′-spirobifluorene derivative bearing thermally cross-linkable vinyl groups (V1382) was developed as a hole-transporting material for perovskite solar cells (PSCs). After thermal cross-linking, a smooth and solvent-resistant three-dimensional (3D) polymeric network is formed such that orthogonal solvents are no longer needed to process subsequent layers. Copolymerizing V1382 with 4,4′-thiobisbenzenethiol (dithiol) lowers the cross-linking temperature to 103 °C via the facile thiol–ene “click” reaction. The effectiveness of the cross-linked V1382/dithiol was demonstrated both as a hole-transporting material in p–i–n and as an interlayer between the perovskite and the hole-transporting layer in n–i–p PSC devices. Both devices exhibit better power conversion efficiencies and operational stability than devices using conventional PTAA or Spiro-OMeTAD hole-transporting materials.