Improving the efficiency of polymer solar cells by incorporating gold nanoparticles into all polymer layers

Abstract

We demonstrate efficiency improvement in polymer solar cells (PSCs) by $22% through incorporating Au nanoparticles (NPs) into all polymer layers. Au NPs are found to have distinct mechanisms in improving device performance when incorporated in different polymer layers. Au NPs in poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate) mainly contribute to better hole collection while Au NPs in active layer contributes to the enhanced optical absorption and more balanced charge-transport. Our theoretical result shows that the absorption enhancement at the active layer is attributed to plasmon resonances with strong near-field distributions penetrated into absorption polymers. These findings can be applied to design high-efficiency metallic NPs-incorporated PSCs. V

Copper nanoparticle incorporated plasmonic organic bulk-heterojunction solar cells

“…% Cu NPs-the median value of PCEs increased from 3.58% to 3.96%, which corresponds to a 10.6% improvement. This relative improvement is lower than that (13.2%-20.4%) for Ag-or Au-NP-based plasmonic devices, [8][9][10][11][12] because the LSPR of Cu NPs is also weaker than those of Ag or Au nanostructures. However, the PCEcost ratio of the Cu NPs is much higher because the price of Cu is much lower than that of Ag or Au.…”

“…13,14 These phenomena depends significantly on the morphology change in the PEDOT:PSS layers. 8,9 In our case, the morphology of PEDOT:PSS layer was only slightly affected by the embedded Cu NPs (see Figs. 2(a) and 2(b)).…”

“…Similar performance degradation has also been observed in the Au-NP-incorporated devices when the concentration of Au NPs is larger than some optimum concentration. 8,9 This performance degradation may be attributed to the increase in light backscattering and decrease in hole conductivity due to the Cu NPs. 10 We also investigated the effects of Cu NPs in the low band gap donor, PTB7-based devices, with the Cu NPs concentration fixed at 0.30 wt.…”

“…6,7 Recently, the localized surface plasmon resonance (LSPR) effects of metallic nanostructures, which enhance light absorption in the visible range, have proven useful in improving performance for P3HT-based device; PCE improvements of 13.2%-20.4% were achieved by adding Au or Ag nanostructures in the poly(3,4-thylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layers. [8][9][10][11][12] For devices based on PTB7 and [6,6]-phenyl-C70-butyric acid methyl ester (PC 70 BM), PCE improvements of 8.9%-10.4% were observed when Ag nanoparticles (NPs) were used. 13,14 A 19.6% improvement was obtained by using both Au and Ag NPs, which exhibit the cooperative plasmonic effect.…”

“…The increase in IPCE and light absorption are typical characteristics of the LSPR effects of metal nanostructures, such as Au and Ag NPs, in organic solar cells. [8][9][10][11][12][13][14] Since J sc is calculated directly by integration of the IPCE over the wavelength spectrum, [8][9][10][11][12][13][14] the increases in J sc in Cu-NP-added samples can be explained by the LSPR effects, which increased the IPCEs of the devices. We calculated the maximum exciton generation rates (G max ) of the control and Cu-NP-added devices, according to the method reported in previous studies.…”