Molecular engineering of conjugated polymers to analyze the correlation between molecular structure and the performance of organic photodetectors
발표자
()
초록
내용
Organic photodetectors (OPDs) have attracted significant interest because of their various benefits such as light weight and mechanical flexibility. Several studies have focused on improving the photocurrent density while reducing dark current density. In this study, we synthesized six benzo[1,2-d:4,5-d’]bis(oxazole)-based conjugated polymers (BBO-based CPs)—PTB1,2,3 and POTB1,2,3—by modifying the presence of an octyl side chain on a thiophene π-spacer (PTBx vs POTBx) and three different alkyl side chains (short linear chain, long linear chain, and branched chain) on the BBO moiety. As a result, POTB1 with octyl thiophene as a π-spacer and a short linear side chain on BBO moiety showed the lowest dark current and superior photocurrent with a responsivity of 0.22 A/W and a specific detectivity of 1.05×10¹³ Jones. Finally, a fingerprint image sensor was fabricated by stacking the POTB1-based OPD on the organic thin-film transistors and we obtained the fingerprint images successfully.