Minimizing structural deformation of gold nanorods in plasmon-enhanced dye-sensitized solar cells

作者：Torngren Bjorn; Sanden Simon; Nyman Johan O; Tiihonen Armi; Jiang Hua; Ruokolainen Janne; Halme Janne; Osterbacka Ronald; Smatt Jan Henrik^*

来源：Journal of Nanoparticle Research, 2017, 19(11): 365.

DOI：10.1007/s11051-017-4062-9

• Gold nanorods
• Plasmon resonance
• Dye-sensitized solar cells
• Deformation
• Low-temperature processing
• Energy conversion
• Thin-film photovoltaics

Plasmonic metal nanoparticles have shown great promise in enhancing the light absorption of organic dyes and thus improving the performance of dye-sensitized solar cells (DSSCs). However, as the plasmon resonance of spherical nanoparticles is limited to a single wavelength maximum (e.g., similar to 520 nm for Au nanoparticles), we have here utilized silica-coated gold nanorods (Au@SiO2 NRs) to improve the performance at higher wavelengths as well. By adjusting the aspect ratio of the Au@SiO2 NRs, we can shift their absorption maxima to better match the absorption spectrum of the utilized dye (here we targeted the 600-800 nm range). The main challenge in utilizing anisotropic nanoparticles in DSSCs is their deformation during the heating step required to sinter the mesoporous TiO2 photoanode and we show that the Au@SiO2 NRs start to deform already at temperatures as low as 200 degrees C. In order to circumvent this problem, we incorporated the Au@ SiO2 NRs in a TiO2 nanoparticle suspension that does not need high sintering temperatures to produce a functional photoanode. With various characterization methods, we observed that adding the plasmonic particles also affected the structure of the produced films. Nonetheless, utilizing this low-temperature processing protocol, we were able to minimize the structural deformation of the gold nanorods and preserve their characteristic plasmon peaks. This allowed us to see a clear redshift of the maximum in the incident photon-to-current efficiency spectra of the plasmonic devices (Delta lambda similar to 14 nm), which further proves the great potential of utilizing Au@SiO2 NRs in DSSCs.

• 出版日期2017-11-3