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Dye-sensitized solar cells (DSSCs) hold unique promise in solar photovoltaics owing to their low-cost fabrication and high efficiency in ambient conditions. However, to improve their commercial viability, effective, and low-cost methods must be employed to enhance their light harvesting capabilities, and hence photovoltaic (PV) performance. Improving the absorption of incoming light is a critical strategy for maximizing solar cell efficiency while overcoming material limitations. Mesoporous silica nanoparticles (MSNs) were employed herein as a reflective layer on the back of transparent counter electrodes. Chemically synthesized MSNs were applied to DSSCs via bar coating as a facile fabrication step compatible with roll-to-roll manufacturing. The MSNs diffusely scatter the unused incident light transmitted through the DSSCs back into the photoactive layers, increasing the absorption of light by N719 dye molecules. This resulted in a 20% increase in power conversion efficiency (PCE), from 5.57% in a standard cell to 6.68% with the addition of MSNs. The improved performance is attributed to an increase in photon absorption which led to the generation of a higher number of charge carriers, thus increasing the current density in DSSCs. These results were corroborated with electrochemical impedance spectroscopy (EIS), which showed improved charge transport kinetics. The use of MSNs as reflectors proved to be an effective practical method for enhancing the performance of thin film solar cells. Due to silica’s abundance and biocompatibility, MSNs are an attractive material for meeting the low-cost and non-toxic requirements for commercially viable integrated PVs.
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Highly transparent tetraaminophthalocyanine polymer films for DSSC cathodes
An inexpensive, transparent, catalytic, and highly stable material is the holy grail for a dye sensitized solar cell (DSSC) cathode. Despite a near exponential increase in research effort on DSSC cathodes, materials approaching this ideal have yet to be found. Transparent cathodes allow for front and back illumination of the solar cell, enable alternative anode materials and cell designs, and are important both for fundamental research and commercialization of DSSCs. In this work, thin polymeric films of nickel tetraminophthalocyanine (NiTAPc) were tested as a catalytic cathode material in Co(Bipy)-mediated DSSCs. The thin films are highly transparent with a transmittance at 550 nm (T550) of over 95% while maintaining an R ct value below 1.3 Ω cm 2 . The NiTAPc films are inexpensive, fast and easy to generate, and stable to 2000 cyclic voltammetry cycles. Long-term film stability was not realized, and a rise in the R ct over time (days) occurred. However, poly-NiTAPc still represents one of the most transparent and catalytic materials reported to date. While historically phthalocyanines (Pc) have been studied as a dye/sensitizer, this first report of phthalocyanine use as a cathode material demonstrates they have utility on both sides of the DSSC.
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- PAR ID:
- 10065059
- Date Published:
- Journal Name:
- Journal of Materials Chemistry A
- Volume:
- 6
- Issue:
- 6
- ISSN:
- 2050-7488
- Page Range / eLocation ID:
- 2767 to 2774
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/C7TA10167H
