New donor polymer including radical producer for operationally stable organic solar cells
발표자
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초록
내용
Herein, we synthesized Br including semiconducting polymer (P2FBTT-Br) for freezing morphology. The thermal-induced and photo-induced crystallinity and aggregation was investigated by GIWAXS. To forbid the thermal- and photo- induced morphological change, we selected the UV-crosslinking strategy. The bromine, which is attached the end of long alkyl chain in P2FBTT-Br, produced radical and bromine radical attacked tertiary hydrogen. The UV-crosslinked morphology prevented thermal degradation (i.e., phase separation), improving stability under operational condition (18.7% → 90.8% after 90 h at 75 °C and 37.9% → 77.5% after 90 h at AM 1.5G). The increased stability showed same tendency in both combination with the norfullerene acceptor (IEICO-4F) and the fullerene acceptor (PC71BM). In addition, the asymmetric alkyl chain length showed higher solubility in green solvent of 2-methyl anisole.