| 초록 |
Two benzo[1,2-b:4,5-b′]dithiophene (BDT) derivatives with (triisopropylsilyl)acetylene (TIPS) and (4-octylphenyl)acetylene substituents were synthesized as donor and copolymerized with 4,7-bis(4-octylthiophen-2-yl)-2,1,3-benzothiadiazole (BT) and 4,4'-diundecyl-2,2'-bithiazole (BTZ) as acceptor using Stille coupling reaction to afford four new copolymers, namely PTBDT-BT, PTBDT-BTZ, POPEBDT-BT, POPEBDT-BTZ. It was found that all the polymers exhibited deep HOMO energy levels lower than -5.4 eV. The low band gap polymers were successfully achieved for PTBDT-BT (1.67 eV) and POPEBDT-BT (1.67 eV). However, PTBDT-BTZ and POPEBDT-BTZ showed somewhat large band gap of 2.02 and 1.95 eV, respectively. The synthesis, characterization, and photovoltaic properties of these polymers were thoroughly investigated. |
