1. Introduction
Owing to their eco-friendly attributes and cost effectiveness,
dye sensitized solar cells (DSSCs) have emerged as promising
candidates among different generation solar cells [1]. So far the
maximum reported efficiency for DSSCs is approximately 13%,
which is below the theoretical estimate by approximately 20%
[2]. Efforts are therefore underway to enhance DSSC efficiency
through different approaches. So far improvement in efficiency
has been achieved either via light harvesting or by reduced recombination.
In order to improve DSSC efficiency via light harvesting,
various approaches like co-sensitization of TiO2 electrode with
different dyes [3], plasmonic enhancement [4,5] synthesis of new
sensitizers with higher molar extinction coefficients [6] and
incorporation of scattering particles have been implemented [7].
On the other hand, reduced back electron transfer (or recombination)
was achieved using post and pre-treatment of mesoporous
TiO2, blocking layer on FTO, insulating layer on mesoporous TiO2
or co-adsorbents in the electrolyte [8–12].