Fully Solution-Processed Semitransparent Organic Solar Cells with a Silver Nanowire Cathode and a Conducting Polymer Anode

Abstract

We report the fabrication of efficient indium-tin-oxide-free organic solar cells based on poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT: PCBM). All layers of the devices from the lowermost silver nanowire cathode to the uppermost conducting polymer anode are deposited from solution and processed at plastic-compatible temperatures < 200 °C. Owing to the absence of an opaque metal electrode, the devices are semitransparent with potential applications in power-generating windows and tandem-cells. The measured power conversion efficiencies (PCEs) of 2.3 and 2.0 % under cathode-and anode-side illumination, respectively, match previously reported PCE values for equivalent semitransparent organic solar cells using indium tin oxide.Transparent conducting electrodes (TCEs), which make electrical contact to other functional layers for current supply/extraction while also transmitting light, are essential components of optoelectronic devices. State-of-the-art TCEs are made of metal oxides, most

Semi-transparent polymer solar cells

“…AgNW was used as the material in the semi-transparent electrodes on both sides of the OPV cell 77,96 and, more recently, other alternatives to high vacuum processed transparent electrodes such as highly doped PEDOT, 73 PEDOT:PSS:CNTs, 67 graphene, 71 have been implemented in OPV cells. In general, the fully solution-processed cells have been shown to perform similarly to equivalent cells fabricated using a sputtered ITO electrode.…”

“…Several different options have been considered, such as low-temperature annealed indium tin oxide (ITO), [42][43][44][45][46][47][48] a three-layer architecture combining a dielectric layer, an ultra thin metal layer, and a second dielectric layer, [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64] PEDOT, [65][66][67] silver grid, 68 graphene, [69][70][71] carbon nanotubes, 67,72 and silver nanowires (AgNW). [73][74][75][76][77][78] However, the need for a nondestructive deposition technique for the top semi-transparent electrode is probably not the major issue that semi-transparent OPV cells must overcome before becoming an industrially viable solution. Indeed, when the top electrode of an OPV cell is made semi-transparent, the capacity of the solar device to trap the electromagnetic field in the absorber layer diminishes.…”

Effective Electrode Length Enhances Electrical Activation of Nanowire Networks: Experiment and Simulation

“…1,2 Currently, metallic nanowire networks are being investigated as next-generation transparent conductors, 3,4 artificial skins, [5][6][7] and flexible optoelectronic devices. [8][9][10] However, to build reliable materials and devices, it is necessary to be able to tune the sheet resistance, and hence the connectivity between the wires that comprise these networks.…”

The Electrical Properties of Plasma-Deposited Thin Films Derived from Pelargonium graveolens

“…Among different polymers investigated for organic electronics, conducting polymers are used as electrodes and contacts for charge transporting [1], semiconducting polymers are employed as active layers in organic thin film transistors (OTFTs) [2] and organic photovoltaics (OPVs) [3], and insulating polymers are used as dielectric layers in OTFTs [4]. Over the years, much attention has been paid to the development of insulating polymers to replace the conventional gate dielectric materials, mostly silicon dioxide (k~4), to realise flexible thin film transistors (TFTs) with a low operating voltage and high mobility [5,6].…”