Modified structures, optical and photovoltaic characteristics of low energy ions beam irradiated TiO2/TiO2-Graphene thin films as electron transport layer in perovskite solar cell

Abstract

The impact of low energy ions beam (700 keV Ar2+ and 300 keV He1+) irradiation on the modified structures, optical and photovoltaic attributes of the TiO2/TiO2-Graphene (TGr) thin films was reported for the first time. These TiO2/TGr thin films were deposited on the ITO substrate using the doctor blade method. The unexposed (pristine) and ions beam irradiated thin films were characterized using XRD, FE-SEM, UV–Vis spectroscopy and solar simulator to determine the interaction mechanism between the low energy ions beam and thin films useful for the perovskite solar cells. The XRD analyses of the TiO2/TGr thin films revealed an insignificant impact of the low energy ions beam irradiation, indicating an excellent structural stability of the grown films. The FESEM analyses of the irradiated thin films supported the XRD results, reaffirming an insignificant change in the particle size distribution. The figure of merit (FOM) of the low energy ions beam irradiated TGr thin films was amplified by a factor of 10 as obtained from the electrical conductivity measurement. It was shown that the stability and FOM of the TGr thin film can be improved via the low energy ions beam exposure, enabling it a better candidate as electron transport layer for the development of perovskite solar cells.