| 초록 |
A novel alternating Diketopyrrolopyrrole copolymer synthesized by Sille coupling reaction for use in polymer solar cells is composed of difluoro-quinoxline (5,8-dibromo-2,3-didodecyl-6,7-difluoroquinoxaline) and dithiophene-difluoro-quinoxline(5,8-bis(5-bromothiophen-2-yl)-2,3-didodecyl-6,7-difluoroquinoxaline). The optical properties of polymers were observed λmax at 742~801 nm in CB solution and at 753~807 nm in thin film state, Egopt at 1.86 eV. The absorption spectra of difluoro-quinoxline (5,8-dibromo-2,3-didodecyl-6,7-difluoroquinoxaline) showed around 50 nm red-shift in both solution and solid film state compare to dithiophene-difluoro-quinoxline(5,8-bis(5-bromothiophen-2-yl)-2,3-didodecyl-6,7-difluoroquinoxaline). A highest molecular orbital (HOMO) energy level displayed its figure in the range of -5.28 ~ -5.46 eV. The polymer DPP-DFQx showed a highest value of 3.49% power conversion efficiency (PCE) and value of 0.65 V open-circuit voltage (Voc). |
