N-type dopants for efficient solar cells

US11380852B2 · kind B2 · utility

Assignees

• The Regents of the University of California · US
• MITSUBISHI CHEMICAL CORPORATION · JP

Inventors

• Julia Schneider · Harburg, DE
• Michael L. Chabinyc · Mountain View, US
• Hengbin Wang · Midland School, US
• Hidenori Nakayama · Goleta, US
• Kyle D. Clark · Midland School, US
• Javier Read de Alaniz · Midland School, US

Key dates

• Filing date: Dec 12, 2019
• Grant date: Jul 5, 2022
• Expiry date: Dec 12, 2039

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10K30/50
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Triazabicylodecene can effectively n-dope a variety of organic semiconductors, including PCBM, thus increasing in-plane conductivities. We synthesized a series of TBD-based n-dopants via an N-alkylation reaction and studied the effect of various alkyl chains on the physical and device properties of the dopants. Combining two TBD moieties on a long alky chain gave a solid dopant, 2TBD-C10, with high thermal stability above 250° C. PCBM films doped by 2TBD-C10 were the most tolerant to thermal annealing and reached in-plane conductivities of 6.5×10−2 S/cm. Furthermore, incorporating 2TBD-C10 doped PCBM as the electron transport layer (ETL) in methylammonium lead triiodide (MAPbI3) based photovoltaics led to a 23% increase in performance, from 11.8% to 14.5% PCE.