Surface Plasmonic Effects of Metallic Nanoparticles on the Performance of Polymer Bulk Heterojunction Solar Cells

Abstract

We have systematically explored how plasmonic effects influence the characteristics of polymer photovoltaic devices (OPVs) incorporating a blend of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM). We blended gold nanoparticles (Au NPs) into the anodic buffer layer to trigger localized surface plasmon resonance (LSPR), which enhanced the performance of the OPVs without dramatically sacrificing their electrical properties. Steady state photoluminescence (PL) measurements revealed a significant increase in fluorescence intensity, which we attribute to the increased light absorption in P3HT induced by the LSPR. As a result, the rate of generation of excitons was enhanced significantly. Furthermore, dynamic PL measurements revealed that the LSPR notably reduced the lifetime of photogenerated excitons in the active blend, suggesting that interplay between the surface plasmons and excitons facilitated the charge transfer process. This phenomenon reduced the recombination level of geminate excitons and, thereby, increased the probability of exciton dissociation. Accordingly, both the photocurrents and fill factors of the OPV devices were enhanced significantly. The primary origin of this improved performance was local enhancement of the electromagnetic field surrounding the Au NPs. The power conversion efficiency of the OPV device incorporating the Au NPs improved to 4.24% from a value of 3.57% for the device fabricated without Au NPs.

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].…”

“…performance [4]. The effective reported thickness for the active layer (~ 100-200 nm) [4][5][6] is too low for a complete absorption of the incident light within the absorption range of the active layer.…”

“…It has been reported that intensifying the electromagnetic (EM) field of the incident light via localized surface plasmon resonance (LSPR) in metallic nano-particles/structures (MNPs) helped in improving the absorption of the active layer with no need for increasing its thickness [4,7]. LSPR occurs when the frequency of the electric field of the incident light resonates with the oscillations of MNPs conduction electrons.…”

Environmentally-friendly solvent processed fullerene-free organic solar cells enabled by screening halogen-free solvent additives

“…2d (J ph = J L −J D , where J L is the current density under illumination and J D is the current density in the dark. V eff = V o −V a , where V a is the applied voltage and V o is the voltage at which J ph is zero) [62]. The exciton dissociation probabilities (P diss ) were calculated to be 83.8%, 84.8%, 85.6%, and 87.3% for the PBDB-T:IT-M-based devices processed by XY, XY/1% ; (c) photovoltaic parameters (PCE, J sc , V oc , and FF) of PSCs processed using different solvent additives; (d) J ph versus V eff plots of the optimal devices processed using different solvent additives.…”

Organic solar cells with plasmonic layers formed by laser nanofabrication

“…[32][33][34] On the contrary, in dense particle films the absorption of previous studies. 35,36 The lower PL quenching can be attributed to the strong local electric field at the particles' vicinity which promotes the exciton dissociation. [32][33][34] Furthermore, the high density of particles with small separation distances causes an extra shadowing effect, undesirable for high efficiency photovoltaics.…”