A five-fold efficiency enhancement in dye sensitized solar cells fabricated with AlCl3 treated, SnO2 nanoparticle/nanofibre/nanoparticle triple layered photoanode

• Published in: Journal of applied electrochemistry 2018-11, Vol.48 (11), p.1255-1264
• Main Authors: Senadeera, G. K. R., Weerasinghe, A. M. J. S., Dissanayake, M. A. K. L., Thotawatthage, C. A.
• Format: Article
• Language: English
• Subjects: Aluminum chloride; Aluminum oxide; Chemistry; Chemistry and Materials Science; Dye-sensitized solar cells; Dyes; Efficiency; Electrochemical impedance spectroscopy; Electrochemistry; Electron recombination; Industrial Chemistry/Chemical Engineering; Irradiance; Light; Nanofibers; Nanoparticles; Photoanodes; Photovoltaic cells; Physical Chemistry; Research Article; Solar Cells; Thickness; Tin dioxide
• ISSN: 0021-891X; 1572-8838
• DOI: 10.1007/s10800-018-1247-6

The use of electrospun nanofibre (NF) membrane of SnO 2 toward the efficiency enhancement in dye sensitized solar cells (DSSCs) with a triple layered, AlCl 3 treated SnO 2 -based photoanode is presented. The performance of DSSCs fabricated with SnO 2 nanoparticle (NP)-based photoanode is compared with that of DSSCs made with a novel triple layered SnO 2 photoanode of configuration FTO/NP/NF/NP. Thickness of the NF membrane is optimized to achieve the highest solar cell performance. Solar cells made with single layer SnO 2 NP photoanode sensitized either by Eosin-Y dye or Indoline dye showed efficiencies of 0.3% and 2.02%, respectively, under the irradiance of 100 mW cm −2 (AM 1.5), while the corresponding devices with AlCl 3 -treated, triple layered photoanode showed efficiencies of 1.55 and 2.77%, respectively, under the same illumination. Accordingly, more than five-fold enhancement in overall efficiency is achieved in DSSCs by using this novel SnO 2 -based photoanode with the optimized thickness of the SnO 2 nanofibre membrane and sensitized with Eosin-Y dye. Scanning electron microscopic studies revealed that the SnO 2 nanofibre membrane consists of an interconnected network-like structure formed by the SnO 2 nanofibres. Electrochemical impedance spectroscopy measurements on DSSCs made with these two types of photoanodes reveals that the series resistance of the DSSC made with the novel NP/NF/NP triple layered photoanode is significantly reduced. The observed higher electron lifetime determined from Bode plots shows that electron recombination is lower in the DSSCs made with the triple layered photoanode. Improved light harvesting by multiple scattering effects within the triple layered photoanode structure and the suppression of the electron recombination by Al 2 O 3 sub-nanometer-sized coating around SnO 2 appear to be the major factors for the enhancement in photo current density and efficiency. Graphicasl Abstract