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.
morphology optimization
ternary small molecule solar cells
thick films
alloy donors
Author
Qunping Fan
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
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
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
Zhengzhou University
Small Methods
23669608 (eISSN)
Vol. 4 3 1900766Subject Categories
Materials Chemistry
Other Chemistry Topics
Condensed Matter Physics
DOI
10.1002/smtd.201900766