Pulsed-laser-ablation based nanodecoration of multi-wall-carbon nanotubes by Co–Ni nanoparticles for dye-sensitized solar cell counter electrode applicationsReport as inadecuate




Pulsed-laser-ablation based nanodecoration of multi-wall-carbon nanotubes by Co–Ni nanoparticles for dye-sensitized solar cell counter electrode applications - Download this document for free, or read online. Document in PDF available to download.

Materials for Renewable and Sustainable Energy

, 6:11

First Online: 12 May 2017Received: 29 March 2017Accepted: 04 May 2017DOI: 10.1007-s40243-017-0095-3

Cite this article as: Imbrogno, A., Pandiyan, R., Barberio, M. et al. Mater Renew Sustain Energy 2017 6: 11. doi:10.1007-s40243-017-0095-3

Abstract

We report here on the use of pulsed KrF-laser deposition technique PLD for the decoration of Multi-wall carbon nanotubes MWCNTs by Co–Ni nanoparticles NPs to form highly efficient counter electrodes CEs for use in Dye-sensitized solar cells DSSC. By varying the number of laser ablation pulses NLP = 500–60,000 of the KrF laser, we were able to control the average size of the Co–Ni NPs and the surface coverage of the MWCNTs by the nanoparticles. The PLD-based decoration of MWCNTs by Co–Ni NPs is shown to form novel counter electrodes, which significantly enhance the power conversion efficiency PCE of the DSSCs. Indeed, the DSSCs based on the PLD-decorated Co–Ni counter electrodes obtained at the optimal NLP = 40,000 are shown to exhibit a PCE value as high as 6.68%, with high short circuit current Jsc = 14.68 mA-cm and open circuit voltage Voc = 0.63 V. This represents a PCE improvement of ~190% in comparison to the DSSCs with pristine MWCNTs PCE = 2.3% and ~7.4% PCE increase than that of the conventional DSSC made with a sputtered Platinum-based counter electrode. By systematically investigating the local nanostructure of the Co–Ni decorated CEs, we found that the Co–Ni NPs layer exhibits a porous cauliflower-like morphology, of which surface roughness RMS is NLP dependent. Interestingly, both PCE and roughness of the Co–Ni NPs layer are found to exhibit the same NLP dependence, with a maximum located around the optimal NLP value of 40,000. This enabled us to establish, for the first time, a linear correlation between the achieved PCE of DSSCs and the local roughness of their CEs decorated by Co–Ni NPs. Such a correlation highlights the importance of maximizing the surface area of the Co–Ni coated MWCNTs on the CEs to enhance the PCE of the DSSCs. Finally, Ultra-violet Photoelectron Spectroscopy UPS measurements revealed a significant decrease in the local work function Φ of Co–Ni NPs decorated MWCNTs based CEs at NLP = 40,000, Φ = 3.9 eV with respect to that of either pristine MWCNTs Φ = 4.8 eV or sputtered-Pt Φ = 4.3 eV counter-electrodes. This Φ lowering of the Co–Ni-MWCNTs based CEs is an additional advantage to enhance the catalytic reaction of the redox couple of the electrolyte solution, and improve thereby the PCE of the DSSCs.

KeywordsPulsed-laser deposition PLD Co–Ni nanoparticles Nanoparticles-CNTs nanohybrids UPS Work function DSSC counter electrode Dye sensitized solar cells 



Author: Alessandra Imbrogno - Rajesh Pandiyan - Marianna Barberio - Anastasia Macario - Assunta Bonanno - My Ali El khakani

Source: https://link.springer.com/







Related documents