| 초록 |
A new series of solar cells (EH-BDT(DTDFDDoQx)2, EH-BDT(DTDFDHexQx)2, Oct-BDT(DTDFDDoQx)2, Oct-BDT(DTDFDHexQx)2) were designed and synthesized. The benzodithiophene (BDT) unit was used as electron rich unit and quinoxaline (Qx) unit was used as electron poor unit to make donor-acceptor type small molecular solar cells. According to alkyl length of benzodithiophene and quinoxaline, the characteristics of organic solar cells were compared. These small molecular showed an optical band gap of 2.06-2.11 eV, with highest occupied molecular orbital (HOMO) energy around -5.30 eV and lowest unoccupied molecular orbital (LUMO) energy around -3.22 eV. The small molecular displayed λmax in solution (475, 471, 475 and 468 nm) and in film (538, 536, 538 and 540) state. The power conversion efficiencies (PCE) of the small molecular solar cell devices made by using molecule: PC70BM blend was 1.20%, 1.07%, 0.88%, and 0.63% respectively. |
