Two Semi-crystalline Polymers with Different Fluorine Topology for Non-Fullerene Solar Cell Performance
발표자
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초록
내용
Two fluorine atoms are substituted on the phenylene moiety in an anti (PTBDD2F-a) or a syn (PTBDD2F-s) fashion for use in nonfullerene organic solar cells (NFOSCs). The two polymers exhibit different interchain packing and film morphologies in both pristine and blend films with an n-type acceptor (ITIC). In grazing incidence X-ray scattering measurements, PTBDD2F-a:ITIC shows more pronounced out-of-plane (010) peaks, suggesting stronger face-on cofacial packing of ITIC molecules in the PTBDD2F-a:ITIC blend. A higher domain purity (1.00 vs. 0.71) is also observed for PTBDD2F-a:ITIC compared to PTBDD2F-s:ITIC in the resonant soft X-ray scattering measurements. These different morphological features induce ∼2.5 times higher hole mobility and ∼6 times higher electron mobility with higher power conversion efficiency (6.60 vs. 5.47%) for PTBDD2F-a:ITIC than for PTBDD2F-s:ITIC. This comparative study highlights the effects of different fluorine topologies along the polymer backbone.