University of California

Mitsubishi Chemical Corporation

The Mitsubishi Chemical Corporation, a Japanese Corporation

Hidenori Nakayama

Michael L Chabinyc

Hengbin Wang

Kyle D Clark

Javier Read De Alaniz

Julia Schneider

Fred Wudl

Yonghao Zheng

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 6.5×10S/cm. Furthermore, incorporating 2TBD-C10 doped PCBM as the electron transport layer (ETL) in methylammonium lead triiodide (MAPbI) based photovoltaics led to a 23% increase in performance, from 11.8% to 14.5% PCE.

N-type dopants for efficient solar cells

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&#xb0; C. PCBM films doped by 2TBD-C10 were the most tolerant to thermal annealing and reached in-plane conductivities of 6.5&#xd7;10S/cm. Furthermore, incorporating 2TBD-C10 doped PCBM as the electron transport layer (ETL) in methylammonium lead triiodide (MAPbI) based photovoltaics led to a 23% increase in performance, from 11.8% to 14.5% PCE.

Sulfur-fused perylene diimides (PDIs) having the formula 2PDI-nS, wherein n is an integer. Such sulfur-fused PDIs (e.g., 2PDI-2S, 2PDI-3S, and 2PDI-4S) are incorporated as electron acceptors in an active region of a bulk heterojunction solar cell and/or as an electron transport layer. Example solar cells exhibit a power conversion efficiency above 5% and a fill factor above 70% (a record high for non-fullerene bulk heterojunction solar cell devices) when 2PDI-nS is used as the electron acceptor. In addition, the solar cells exhibit low open circuit voltage (V) loss.

Efficient solar cells via sulfur-fused helical perylene diimides design concept

Growing community of inventors

Goleta, CA, United States of America

Hidenori Nakayama