| 초록 |
Benzotriazole (BTZ) units are known for relatively weak electron acceptors compared to benzothiadiazole, diketopyrrolopyrrole, and quinoxaline building blocks. However BTZ-based copolymers can still achieve over 7% of power conversion efficiency in organic photovoltaics even though they had medium band gap. These results can be speculated in employing a tandem cell structure with two active layers absorbing different parts of the solar spectrum. Here we present the synthesis and properties of the π-conjugated small molecule, oligomer and polymer containing a BTZ building block as an acceptor alternated with a carbazole donor. A small conjugated molecule, BTZCZ-2, was prepared for comparing the effects of molecular weights on the OPV performance fabricated by conventional and inverted solar cell devices. The best power conversion efficiency (over 5%) was achieved from BTZCZ-2/PC[71]BM with a PEIE/ZnO interlayer in the inverted solar cell architecture. |
