A competitive new technology, organic metallic halide perovskite solar cells feature a wide working area, low manufacturing costs, a long lifespan, and a significant amount of large efficacy of power conversion (PCE). The spin-coating technique was utilized for the fabrication of pure CH3NH3PbBr3 (MAPbBr(3)) thin films, and these films are implanted with 600 keV silver (Ag) ions at fluency rate of 6 x 10(14) and 4 x 10(14) ions/cm(2). XRD analysis confirmed the cubic structure of MAPbBr(3). A high grain size was observed at the fluency rate of 4 x 10(14) ions/cm(2). The UV-Vis spectroscopic technique was used to calculate the optical properties such as the bandgap energy (E-g), refractive index (n), extinction coefficients (k), and dielectric constant. A direct E-g of 2.44 eV was measured for the pristine film sample, whereas 2.32 and 2.36 eV were measured for Ag ion-implanted films with a 4 x 10(14) and 6 x 10(14) ions/cm(2) fluence rate, respectively. The solar cells of these films were fabricated. The J(sc) was 6.69 mA/cm(2), FF was 0.80, V-oc was 1.1 V, and the efficiency was 5.87% for the pristine MAPbBr(3)-based cell. All of these parameters were improved by Ag ion implantation. The maximum values were observed at a fluency rate of 4 x 10(14) ions/cm(2), where the V-oc was 1.13 V, FF was 0.75, J(sc) was 8.18 mA/cm(2), and the efficiency was 7.01%.