TY - JOUR
T1 - Synergistic Effects of Side-Chain Engineering and Fluorination on Small Molecule Acceptors to Simultaneously Broaden Spectral Response and Minimize Voltage Loss for 13.8% Efficiency Organic Solar Cells
AU - Fan, Qunping
AU - Su, Wenyan
AU - Zhang, Ming
AU - Wu, Jingnan
AU - Jiang, Yufeng
AU - Guo, Xia
AU - Liu, Feng
AU - Russell, Thomas P.
AU - Zhang, Maojie
AU - Li, Yongfang
N1 - Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/11/1
Y1 - 2019/11/1
N2 - Herein, three small molecule (SM)-acceptors (POIT-IC, POIT-IC2F, and POIT-IC4F) are developed by combining the side-chain engineering located on the sp3-hybridized carbon atoms of the fused-ring core and the fluorination of end groups. From ITIC to POIT-IC, POIT-IC2F, and then to POIT-IC4F, the SM-acceptors show gradually broadened absorption spectra, increased maximum extinction coefficient, crystallinity, and electron mobilities due to the synergistic effects of side-chain engineering and fluorination. Compared with nonfluorinated ITIC and POIT-IC, as fluorination broadens the molecular spectra, POIT-IC2F and POIT-IC4F with alkoxyphenyl side chains show less decreased LUMO levels than IT-IC2F and IT-IC4F with alkylphenyl side chains, which are conducive to both higher Voc and Jsc for organic solar cells (OSCs). Combined with polymer donor PM6, the POIT-IC4F-based OSCs achieve a device efficiency of up to 13.8% with a high Voc of 0.91 V and Jsc of 20.9 mA cm−2, which are significantly higher than that of the control OSCs based on ITIC (8.9%), POIT-IC (10.1%), or IT-IC4F (12.2%). An efficiency of 13.8% is one of the highest PCEs reported for the annealing-free OSCs. Our results show that the synergistic effects of side-chain engineering and fluorination on SM-acceptor can simultaneously broaden spectral response and minimize voltage loss of OSCs and ultimately achieve high device efficiency.
AB - Herein, three small molecule (SM)-acceptors (POIT-IC, POIT-IC2F, and POIT-IC4F) are developed by combining the side-chain engineering located on the sp3-hybridized carbon atoms of the fused-ring core and the fluorination of end groups. From ITIC to POIT-IC, POIT-IC2F, and then to POIT-IC4F, the SM-acceptors show gradually broadened absorption spectra, increased maximum extinction coefficient, crystallinity, and electron mobilities due to the synergistic effects of side-chain engineering and fluorination. Compared with nonfluorinated ITIC and POIT-IC, as fluorination broadens the molecular spectra, POIT-IC2F and POIT-IC4F with alkoxyphenyl side chains show less decreased LUMO levels than IT-IC2F and IT-IC4F with alkylphenyl side chains, which are conducive to both higher Voc and Jsc for organic solar cells (OSCs). Combined with polymer donor PM6, the POIT-IC4F-based OSCs achieve a device efficiency of up to 13.8% with a high Voc of 0.91 V and Jsc of 20.9 mA cm−2, which are significantly higher than that of the control OSCs based on ITIC (8.9%), POIT-IC (10.1%), or IT-IC4F (12.2%). An efficiency of 13.8% is one of the highest PCEs reported for the annealing-free OSCs. Our results show that the synergistic effects of side-chain engineering and fluorination on SM-acceptor can simultaneously broaden spectral response and minimize voltage loss of OSCs and ultimately achieve high device efficiency.
KW - fluorination
KW - organic solar cells
KW - power conversion efficiency
KW - side-chain engineering
KW - small molecule acceptors
UR - http://www.scopus.com/inward/record.url?scp=85078938271&partnerID=8YFLogxK
U2 - 10.1002/solr.201900169
DO - 10.1002/solr.201900169
M3 - Journal article
AN - SCOPUS:85078938271
SN - 2367-198X
VL - 3
JO - Solar RRL
JF - Solar RRL
IS - 11
M1 - 1900169
ER -