[3PS-276]
Side chain effect of benzodithiophene on the diketopyrrolopyrrole-based copolymer for the opto-electronic properties
발표자Karina Ayu Larasati (Gyeongsang National University)
연구책임자김윤희 (Gyeongsang National University)
Abstract
This study explores the synthesis and properties of two DPP-based copolymers, PBDTTT-DPP-C12 and PBDTTT-DPP-C17, differing in alkyl side chains. Both were synthesized via alkylation, lithiation, bromination, and Stille coupling. Structures were confirmed by ¹H NMR. Thermal analysis showed high stability with decomposition temperatures of 377 °C and 367 °C, respectively. UV–Vis spectra showed dual-band absorption with λmax at 669 nm (C12) and 700 nm (C17), slightly red-shifted in film. Electrochemical studies via CV showed similar HOMO levels (−5.22 eV and −5.23 eV) and LUMO levels (1.47 eV and 1.49 eV). GIWAXS and AFM revealed PBDTTT-DPP-C12 had more edge-on orientation. In OPV devices, PBDTTT-DPP-C17 achieved higher PCE (2.8%) than C12 (1.8%). These results highlight how side-chain engineering impacts morphology, crystallinity, and solar cell efficiency in DPP polymers.