Polymer solar cells fabrication

Krebs FC, Tromholt T, Jorgensen M (2010) Upscaling of polymer solar cell fabrication using full roll-to-roll processing. Nanoscale 2 873... 

Park. B. Han M. (2009). Photovoltaic characteristics of polymer solar cells fabricated by pre-metered coating process. Optics Express, vol. 17, no. 16,13830-13840. 

J. Y. Kim, K. Lee, N. E. Coates, D. Moses, T.-Q. Nguyen, M. Dante, A. J. Heeger, Efficient Tandem Polymer Solar Cells Fabricated by All-Solution Processing. Science 2007,317,222-225. 

J.Y. Kim, et al.. Efficient tandem polymer solar cells fabricated by all-solution processing. Science, 2007. 317 p. 222-225. 

Figure 6.2 (a) Schematic of the ESSENCIAL process for fabricating polymer solar cells (al) applying blend solution (a2) active layer formation during solvent evaporation under pressure (a3) isolated island-type electrode deposition on top of polymer blend film after removing the PDMS stamp. Note that PEDOT PSS layer is not indispensable to this processing as described in the text, (b) Roll-to-roll processing for polymer solar cells (bl) schematic of roll-to-roll process for polymer solar cell fabrication (b2) a schematic to depict... 

Krebs FC (2009) Fabrication and processing of polymer solar cells a review of printing and coating techniques. Sol Energy Mater Sol Cells 93 394... 

To summarize this section, we can say that the measurements made by us and by many other groups appear to be inconsistent with general physical concepts. Though this behavior has been observed in solar cells fabricated with different organic materials and with different structures, the polymer scientists have not discussed reasons for this behavior. 

The application of polymer precursors, resulting in insoluble PPV and BBL (poly(benzimidazo-benzophenanthroline)) ladder polymers enabled the fabrication of very efficient bilayer polymer solar cells, reaching 49% [33] and even 62% EQE (see Fig. 45) [222]. 

Recently the idea of Ago et al. to replace the ITO electrode by a CNT based electrode was pursued by several groups again. However, this time SWNTs were used [330-333]. The motivation for this step is generally found in the benefit of replacing an expensive vacuum step in the fabrication of polymer solar cells [330] with roll-to-roll production of supporting nanotube electrodes (Fig. 67) [331], which will aid in the removal of ITO and PEDOT PSS related problems [332] while facilitating applications of flexible devices on plastic substrates [333]. 

Transparent polymer solar cells (i.e., polymer solar cells with transparent electrodes) can be easily fabricated based on inverted architecture and have important application in tandem architectures as well. We can form transparent solar cells by replacing the Al top electrode with 12 nm Au in the inverted structure. The J-V curves for this transparent polymer solar cell, with light incident from ITO and Au side, are shown in Figure 11.17. The difference between the two J-V curves is due to the partial loss by the reflection and absorption at the semitransparent Au electrode. To provide sufficient electrical conductance, Au layer thickness has to be sufficient and the optical loss at Au electrode becomes significant. However, the inverted solar cell structure has the V2O5 layer which is not only transparent but also provides effective protection to the polymer layer. A transparent conductive oxides electrode, such as ITO, can therefore be deposited without compromising device performance. 

Polymer solar-cell devices based on a blend of poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester, and incorporating doped PANI-NTs as an interfacial layer, have been fabricated [511,512]. The power-conversion efficiency of an annealed device incorporating the PANI-NTs layer showed an increase of 26% relative to that of the annealed device lacking the PANI-NTs interfacial layer. The high conductivity, controlled tubular nanoscale morphologies, and mobility of the annealed PANI-NTs layer led to efficient extraction of photogenerated holes to the buffer layer and suppression of exciton recombination, thereby improving the photovoltaic performance. 

FIGURE 3.4 (A) Fabrication of polymer solar cell from PEDOTiPSS thin film. (B) Fabrication of a three-dimensional (3D) nonwoven nanofabric-based organic solar cell. (A) Reproduced with permission from reference Oh, J.Y., Shin, M., Lee, J.B., Ahn, J.-H., Baik, H.K., Jeong, U., 2014. Effect ofPEDOT nanofibril networks on the conductivity, flexibility, and coatability of PEDOT PSS films. ACSAppl. Mater. Interfaces 6, 6954-6961. Copyright 2014, Royal Society of Chemistry. 

Polymer solar cell Typically the p-type conducting polymer can be applied as hole transporting material, and the mostly used is PEDOTPSS in polymer solar cell. This material has been studied thoroughly and fabricated into one-dimensional nanostructured network... 

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