[en] Highlights: • BFO/BTO multilayers of varying layer number deposited on Pt/Si using CSD technique • 100 MeV Au^{+ 8} irradiation performed at fluences 1 × 10¹², 1 × 10¹³ and 3 × 10¹³ ions/cm² • Irradiation effects on photovoltaic response studied in MFM capacitor configuration • Photovoltaic response sustained in multilayer structures post ion beam irradiation This work presents the swift heavy ion (SHI) irradiation induced possible modifications in structural strain and surface morphology of (BiFeO₃)BFO/(BaTiO₃)BTO multilayer structures prepared by chemical solution deposition technique. Furthermore, the role of structural defects (induced due to irradiation) on the ferroelectric property and photovoltaic response of BFO/BTO multilayer structures having different number of layers has been studied. Significant modifications in the morphological and ferroelectric properties of BFO/BTO (two, four and six layers) multilayer structures due to induced structural defects were observed after SHI irradiation performed using 100 MeV Au^{+ 8} ion with ion fluence of ~ 1 × 10¹², 1 × 10¹³ and 3 × 10¹³ ions/cm². Ferroelectric photovoltaic response decreases with increase in ion fluence from 1 × 10¹² to 1 × 10¹³ ions/cm² along with change in open circuit voltage from 0.41 V to 0.23 V, short circuit current density from 5.177 μA/cm² to 1.71 μA/cm² and I_on/I_off ratio from 33.02 to 13.02. This study on effect of SHI irradiation on multilayer ferroelectric photovoltaic cell is important to understand the possible application of BFO/BTO multilayer photovoltaic cells in the regions susceptible to radiations. Furthermore, the study of perovskite solar cell performance in the presence of SHI radiation, is essentially required for the development of durable solar energy harvesters.