Plasmonic-enhanced polymer photovoltaic devices incorporating solution-processable metal nanoparticles

Abstract

We have explored the effect of gold nanoparticle ͑Au NP͒-induced surface plasmons on the performance of organic photovoltaic devices ͑OPVs͒. The power conversion efficiency of these OPVs was improved after blending the Au NPs into the anodic buffer layer. The addition of Au NPs increased the rate of exciton generation and the probability of exciton dissociation, thereby enhancing the short-circuit current density and the fill factor. We attribute the improvement in device performance to the local enhancement in the electromagnetic field originating from the excitation of the localized surface plasmon resonance.

Optically-enhanced performance of polymer solar cells with low concentration of gold nanorods in the anodic buffer layer

“…7b the increase in the EQE via incorporating the 15% Au NRs in ABL solution. We found that the EQE was enhanced by up to 12-14% respectively around 520-640 nm, which are near to the transverse absorption reported results similar to ours with the EQE curves for both reference and NPs devices having the same absorption ranges with a slight enhancement in the tail near the IR region [4,11,15].…”

“…For these devices, we observed a clear enhancement in the Jsc from 6.6 to 7.7 mA/cm 2 , which lead to 21.3% enhancement in the PCE. We found such enhancement quite interesting considering the low density of the MNPs in the layer as compared to some reported studies in which the density of the particles was much higher [9,11,15]. The density of the NRs embedded in the ABL of our samples was estimated from the SEM as ~ 6 -8 × 10 8 rods/cm 2 .…”

“…Hence, the number of free charge carriers that reached electrodes would be lowered, thus reducing both Voc and Jsc [7]. It is also possible that the larger density of NRs would prevent some light from reaching the active layer either by scattering or increased absorption in the NRs [15]. Table 1 also shows that by embedding Au NRs in the PEDOT:PSS layer, the devices series resistance (Rs) was reduced by up to 36%, which contributed to the total enhancement in the PCE.…”

“…Hence, introducing MNPs in the anodic buffer layer (ABL) of OSCs would be a good approach. The effect of incorporating non-spherical MNPs into the ABL of BHJ-OSC has not been studied widely whereas all of the earlier studies were performed using relatively spherical particles [14][15]. The fact that the plasmonic absorption mode is a shape-dependent property [19], and the possibility of having higher fraction of the forward-scattered light using cylindrical particles rather than the spherical ones [20] motivate the use of gold nanorods (Au NRs) in the present work.…”

“…The excited MNPs thereby strongly absorb (near-field effect) and scatter (far-field effect) the incident light, producing an enhancement up to a factor of 100 [3], in the electric field surrounding them [8]. Previous studies showed that the PCE of BHJOSCs was improved considerably by MNPs incorporated into OSC layers either on top of indium tin oxide (ITO) [9][10][11][12], within poly(3,4-ethyl-enedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) [13][14][15], within P3HT:PCBM [16], or with the back electrode [17].…”