초록 |
Branching point of naphthalene diimide (NDI)-based conjugated polymers was systematically controlled by incorporating different side chains. The effect of branching point engineering on their properties in terms of optical, electrochemical, structural and charge transport ability was investigated. Interestingly, NDI-based polymers showed enhanced intermolecular interaction in solution as the branching point was moved away from conjugated backbones. As-cast film of P(NDI3-T) and P(NDI4-T) exhibited ordered lamellar diffraction up to third order. After annealing film, molecular ordering was gradually developed in both face-on and edge-on directions. Consequently, P(NDI4-T) exhibited the highest electron mobility of 0.22 cm2 V−1 s−1 in organic field effect transistor. However, in all-polymer solar cell, the highest Jsc was achieved in P(NDI3-T) blended with PBDTTTPD as a donor, resulting in highest PCE of 6.9 %. |