Effect of multi-walled carbon nanotubes on the stability of dye sensitized solar cells

Abstract

h i g h l i g h t s< We studied dye sensitized solar cells with and without addition of carbon nanotubes. < CNTs can improve both photoconversion efficiency and operational stability. t r a c tWe report the improvement of the operational stability of dye-sensitized solar cells (DSSCs) by incorporating multi-wall carbon nanotubes (MWCNTs) in conventional nanostructured semiconducting TiO 2 photoanodes. DSSCs were prepared by adding various concentrations of MWCNTs (up to 1.0% wt.) to TiO 2 anatase nanoparticles. Optimization of MWCNT concentration leads to photoconversion efficiency as high as 4.1% as opposed to 3.7% for pure TiO 2 photoanodes. The performance of the solar cells was measured for 10 consecutive days of continuous ambient light exposure. MWCNT addition results in the decrease of efficiency from 4.1% to 3.7%, while a decrease from 3.7% to 2.4% was recorded in pure TiO 2 photoanodes. These results are encouraging toward the commercial exploitation of DSSCs.

Hybrid Carbon Nanotubes–TiO2 Photoanodes for High Efficiency Dye-Sensitized Solar Cells

“…CNT-based architectures can be used as a conducting scaffold in a TiO 2 semiconductor based photoelectrochemical cell with the effect of increasing the PCE by a factor of 2 (ref 7) or cell stability. 27 Here, we present a simple, fast, and low-cost fabrication method for the integration of MWCNTs in TiO 2 photoanodes to enhance the functional properties of DSCs. The process is highly reproducible and leads to 25% improvement of PCE with respect to the photoanode without adding CNTs.…”

Carbon Nanotubes for Dye-Sensitized Solar Cells

“…Furthermore, several authors have made a similar observation on this optimized value of CNT content and suggested that a concentration range between 0.01 and 0.03 wt% CNTs in TiO 2 fi lms is suitable to achieve high-performance DSSCs. [ 201,213,214 ] It is surprising that this optimized CNT concentration is very different from that (0.1-0.3 wt%) found in some other works.…”

Carbonaceous Dye‐Sensitized Solar Cell Photoelectrodes

“…Since this signifi cant improvement in the DSSC performance was demonstrated by these authors using CNTs, considerable attention has been paid to the research on this topic. [96][97][98][99][100][101][102][103][104][105][106][107][108][109] For instance, Lin et al [ 99 ] prepared bilayer structured photoelectrode fi lms composed of multi-walled carbon nanotubes (MWCNTs)-TiO 2 /TiO 2 which when used in DSSCs exhibited two times higher PV effi ciency than the cell fabricated with the bare TiO 2 fi lm. This improvement in the PV performance has been demonstrated to be related to the 1D CNT which supports transfer of the photo-generated charges quickly, thus suppressing charge recombination.…”

“…In order to obtain a balance between the R ct and IPCE, several efforts have been undertaken with different concentrations of CNTs structures. [ 97,[100][101][102][103][104] In these studies, the optimized concentrations of CNTs in TiO 2 fi lms were relatively different because the corresponding DSSCs were fabricated under different experimental conditions. A general method to prepare CNTs/TiO 2 photoelectrodes is as follows: CNTs are fi rst chemically treated using acid solutions (HNO 3 or H 2 SO 4 ) to generate functional groups such as hydroxyl (-OH), carbonyl (C=O) and carboxyl (-COOH) groups.…”