Effect of organic salt doping on the performance of single layer bulk heterojunction organic solar cell

Abstract

The effect of organic salt, tetrabutylammonium hexafluorophosphate (TBAPF 6) doping on the performance of single layer bulk heterojunction organic solar cell with ITO/MEHPPV:PCBM/Al structure was investigated where indium tin oxide (ITO) was used as anode, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV) as donor, (6,6)-phenyl-C61 butyric acid methyl ester (PCBM) as acceptor and aluminium (Al) as cathode. In contrast to the undoped device, the electric field-treated device doped with TBAPF 6 exhibited better solar cell performance under illumination with a halogen projector lamp at 100 mW/cm 2. The short circuit current density and the open circuit voltage of the doped device increased from 0.54 μA/cm 2 to 6.41 μA/cm 2 and from 0.24 V to 0.50 V, respectively as compared to those of the undoped device. The significant improvement was attributed to the increase of built-in electric field caused by accumulation of ionic species at the active layer/electrode interfaces.