In
the present work, a one-step hydrothermal route was performed
to develop the Cu2ZnSnS4 (CZTS) photoelectrode
onto a conducting substrate. The photovoltaic performance of the homojunction
CZTS photocathode was analyzed with a two-electrode cell system of
FTO/CZTS/(0.3 M Eu3+–Eu2+)aq/graphite. An increase in reaction temperature shows a decrease in
the band gap energy from 1.54 to 1.44 eV. The evolution of the kesterite
CZTS structure with uniform and dense nanospheres was confirmed by
X-ray diffraction (XRD) and field emission scanning electron microscopy
(FE-SEM) studies. High resolution transmission electron microscopy
(HR-TEM) and selected area electron diffraction (SAED) evaluations
confirm the formation of polycrystalline thin films. The photoelectrochemical
solar cell properties of CZTS (C1–C3)
thin films demonstrate an increase in photoconversion efficiency (η)
from 2.55 to 4.87% as a function of reaction temperature. The improvement
in electrical conductivity and generation of lower R
ct and R
s of (C1–C3) thin films were confirmed using electrochemical
impedance spectroscopy.