| Autor: |
Ramoroka ME; SensorLab (University of the Western Cape Sensor Laboratories), Chemical Sciences Building, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa., Mdluli SB; SensorLab (University of the Western Cape Sensor Laboratories), Chemical Sciences Building, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa., John-Denk VS; SensorLab (University of the Western Cape Sensor Laboratories), Chemical Sciences Building, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa., Modibane KD; Department of Chemistry, School of Physical and Mineral Science, University of Limpopo, Sovenga, Polokwane 0727, South Africa., Arendse CJ; Department of Physics and Astronomy, University of the Western Cape, Bellville, Cape Town 7535, South Africa., Iwuoha EI; SensorLab (University of the Western Cape Sensor Laboratories), Chemical Sciences Building, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. |
| Abstrakt: |
This report focuses on the synthesis of novel 2,3,4,5-tetrathienylthiophene-co-poly(3-hexylthiophene-2,5-diyl) (TTT-co-P3HT) as a donor material for organic solar cells (OSCs). The properties of the synthesized TTT-co-P3HT were compared with those of poly(3-hexylthiophene-2,5-diyl (P3HT). The structure of TTT-co-P3HT was studied using nuclear magnetic resonance spectroscopy (NMR) and Fourier-transform infrared spectroscopy (FTIR). It was seen that TTT-co-P3HT possessed a broader electrochemical and optical band-gap as compared to P3HT. Cyclic voltammetry (CV) was used to determine lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy gaps of TTT-co-P3HT and P3HT were found to be 2.19 and 1.97 eV, respectively. Photoluminescence revealed that TTT-co-P3HT:PC 71 BM have insufficient electron/hole separation and charge transfer when compared to P3HT:PC 71 BM. All devices were fabricated outside a glovebox. Power conversion efficiency (PCE) of 1.15% was obtained for P3HT:PC 71 BM device and 0.14% was obtained for TTT-co-P3HT:PC 71 BM device. Further studies were done on fabricated OSCs during this work using electrochemical methods. The studies revealed that the presence of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) on the surface of indium tin oxide (ITO) causes a reduction in cyclic voltammogram oxidation/reduction peak current and increases the charge transfer resistance in comparison with a bare ITO. We also examined the ITO/PEDOT:PSS electrode coated with TTT-co-P3HT:PC 71 BM, TTT-co-P3HT:PC 71 BM/ZnO, P3HT:PC 71 BM and P3HT:PC 71 BM/ZnO. The study revealed that PEDOT:PSS does not completely block electrons from active layer to reach the ITO electrode. |
