| 초록 |
Novel non-conjugated electrolyes were synthesized to apply as a cathode interlayer, which improved power conversion efficiencies (PCEs) of polymer solar cells (PSCs). The electrolytes; V-C4-OTs, V-C6-OTs, and V-C12-OTs contain a viologen skeleton with tosylate anion and alkyl chains of different length. This viologen unit has high electron affinity, low lying reduction potential and generates a favorable interfacial dipole between ZnO layer and an active layer. Furthermore, tosylate anion will increase magnitude of dipole moment. Thus, work function of pristine ZnO and ZnO with V-C4-OTs, V-C6-OTs, and V-C12-OTs indicated -4.4, -4.33, -4.26 and -4.19 eV, respectively. PSCs were fabricated with PTB7 and PC71BM as the active layer. The highest PCE of the device based on V-C12-OTs were achieved up to 8.6%, which is better than the device based on pristine ZnO (7.6 %). In addition, the PCE of the devices based on V-C4-OTs and V-C6-OTs was reached to 8.1 % and 8.3 %, respectively. |
