Weak Makes It Powerful: The Role of Cognate Small Molecules as an Alloy Donor in 2D/1A Ternary Fullerene Solar Cells for Finely Tuned Hierarchical Morphology in Thick Active Layers
Journal article, 2020

Herein, a novel small molecule donor is first developed, FSM6, which is a cognate molecule to BTR possessing similar molecular structure with comparable optical absorption but different crystallinity. The efficient fullerene-type ternary small molecular solar cells (SMSCs) based on an alloy donor of BTR and FSM6 in a thick film of 250 nm reveal the improved hierarchical phase separation morphology and molecular structural order of ternary active layers with improved crystallinity of the key donor component BTR. Furthermore, FSM6 as the key third component also plays a role of charge transfer accelerator in ternary SMSCs. As a result, the optimal ternary SMSCs based on BTR:FSM6:PC71BM achieve a high power conversion efficiency (PCE) up to 10.21% with the synergistically improved open-circuit voltage of 0.950 V, short-circuit current density of 13.85 mA cm(-2), and fill factor of 77.6%, in comparison with either the binary SMSCs of BTR:PC71BM (PCE = 9.37%) or FSM6:PC71BM (PCE = 8.00%). This work provides a promising methodology to optimize device morphology for high-performance ternary SMSCs by combining two cognate small molecules with similar absorption spectra but different crystallinity as an alloy donor.

alloy donors

thick films

morphology optimization

ternary small molecule solar cells

Author

Qunping Fan

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Ergang Wang Group

Tao Liu

Hong Kong University of Science and Technology

Ming Zhang

Shanghai Jiao Tong University

Wenyan Su

Chalmers, Chemistry and Chemical Engineering

Jinan University

Ulises Mendez Romero

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Ergang Wang Group

Tao Yang

Chinese Academy of Sciences

Xinjian Geng

Chalmers, Chemistry and Chemical Engineering

Lintao Hou

Jinan University

Donghong Yu

Aalborg University

Sino-Danish Center for Education and Research Denmark

Feng Liu

Shanghai Jiao Tong University

Beijing Natl Lab Mol Sci

He Yan

Hong Kong University of Science and Technology

Ergang Wang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Ergang Wang Group

SMALL METHODS

2366-9608 (ISSN)

1900766

Subject Categories

Materials Chemistry

Other Chemistry Topics

Condensed Matter Physics

DOI

10.1002/smtd.201900766

More information

Latest update

2/6/2020 1