Abstract
The plasmonic effect of gold nanoparticles has been used in this work to enhance light energy absorption in organic solar cells, to compensate for high light-transmissivity in the active material due to its low thickness. It was found that the density of the nanoparticles grown in the device had a certain critical effect on the performance of the device; where the performance increases with higher nanoparticle density and is optimum when the nanoparticles are grown up for 30 min, which produces a nanoparticle density as high as ca. 125 particles/ μm2. In these conditions, an improvement as high as 83% of the original device can be obtained. The size of the nanoparticles was also found to have a profound effect on the device performance, in which an increase in nanoparticle correlates with a decrease in performance. This is attributed to an increase in the surface roughness at the interface between the active materials and the PEDOT:PSS as the size increases. Gold nanoparticle preparation and a possible mechanism underlying the improvement of the device performance upon the presence of gold nanoparticles will be discussed.
Keywords: Gold nanoparticles, LSPR, organic solar cell, plasmonic.