The most abundant source of renewable energy on earth is sun
light. The proper use of solar energy in a well organized, economical
manner is a challenging research issue. Various kinds of solar
cells (e.g., inorganic, polymer based p–n junction photovoltaic
cells, quantum dot and dye sensitized solar cell, etc.) are developed
till date for harvesting of solar light into electrical energy [1–4]. In
this regard, dye sensitized solar cells (DSSCs) have attracted significant
academic and technological attention due to their simple and
cost-effective fabrication [5]. A typical DSSC is usually composed of
photo-anode (semiconducting metal oxides coated on transparent
conducting glass substrate), photo-sensitizer (dye), counter electrode
and electrolyte [6]. The operating principle of DSSC is
described well in various literatures [7]. As reviewed, for DSSCs,
dye and metal oxide play significant role in the generation, injection
and transportation of photo-excited electrons. The choice of
photo-sensitizers in solar cells is directed mostly based on their
visible light absorption characteristics, stability and cost. Several