Abstract:
Nanomaterials for photovoltaic have gained a lot of attention in the past few years in the
arena of energy. Titania (TiO2) is an important material having found its use in many
technological applications. Due to its large surface-to-volume ratio, TiO2 nanofibers
(NFs) are drawing increased attention in 3rd generation of photovoltaic solar cells such as
DSSC. The electro-optical response of TiO2 can be tuned by metal doping and structural
control at the nano level. In this research, NFs of copper (Cu) doped Titania (TiO2) were
fabricated by using electrospinning. To get Cu doped TiO2 NFs the calcination and
annealing were performed in the air at 500
C for 2 hours. The Energy-Dispersive X-ray
Spectroscopy (EDS) results confirmed the doping of copper inside the titania after
calcination. Scanning electron microscopy (SEM) results show NFs of varying diameters
mostly in the 80 nm to 200 nm regime. SEM of the post-annealed samples shows relatively
rougher fibers of reduced size compared to the uncalcined samples which are due to the
evaporation of PVP and solvents. The increase in roughness and reduction in the NFs
diameter means an increase in the overall surface area and more efficient charge transport
as Hall’s effect results depicted that after doping of copper in nanofibers, the conductivity
of the nanofibers improved by 2 times as compared to undoped nanofibers of titania.
Moreover, Ultraviolet-Visible Spectroscopy (UV-Vis) showed that 1 % Cu doping
decreased the bandgap and the absorption of the spectrum shifted more towards the visible
region of the spectrum. The IV characteristic measurement was performed, and it gave the
efficiency of the prepared solar cell equal to 0.0114 % with Open circuit voltage (VOC)
equal to 0.66 V and short circuit current (ISC) equal to 0.03 mA. The increase in the VOC
is due to the wide bandgap of semiconductor and decreased diameter of nanofibers. The
lower value of the ISC is the result of Cu/electrolyte reaction and low electron injection of
Nanofibrous Cu doped TiO2 photoanode.
