| 초록 |
In BHJ devices, fullerene derivatives such as [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) have been generally used as electron acceptors because of good solubility in organic solvents, high electron mobility, and high electron affinity. However, since these fullerene derivatives have the relatively lower LUMO energy level of 4.3 eV, it is required that polymer donor have deep HOMO energy level in between -5.2 and -5.8 eV to achieve high open circuit voltage and the same time low band gap between 1.2 and 1.9 eV for maximum solar absorption. For this condition to be realized, we successfully synthesized thieno[3,4-d]thiazole, and introduced the thiazole ring with strong electron-withdrawing ability in donor polymer to lower both HOMO and LUMO energy levels. |
