Abstract
A conjugated alternating copolymer as the donor material of the active layer in polymer solar cells has been designed and synthesized via Stille coupling reaction. The alternating structure consisted of 3,5-didecanyldithieno(3,2- b:2!,3!-d)thiophene (DDTT) donor unit and 5,6-bis(tetradecyloxy)benzo-2,1,3-thiadiazole (BT) acceptor unit. Since both units have been attached pendant chains, the polymer was soluble in common organic solvents. UV-vis spectrum exhibited a broad absorption band in the range of 270-780 nm and a low bandgap of 1.83 eV. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the polymer were estimated to be -5.10 and -3.27 eV, respectively. Based on the ITO/PEDOT:PSS/PDDTTBT:PCBM/Al device structure, the power conversion effi- ciency (PCE) under the illumination of AM 1.5 (100 mW/cm 2 ) was 0.127%. The effects of annealing temperature (50- 150°C) for 30 min on the device performance were studied. It was found that PCE of 0.292% could be acquired under the annealing condition at 50°C for 30 min. The improved device efficiency under the optimal condition was confirmed by the higher light harvest in UV-vis spectra, the enhanced quenching of photoluminescence (PL) emission, and the improved nanoscale morphology by atomic force microscopy (AFM) examination.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
