Planar perovskite solar cell (PSC) measuring 900 nm total thickness is designed and simulated using Silvaco and SCAPS. Silvaco (Atlas 5.16.3.R) photovoltaic simulating system enables the formation of the stacking model and estimation of the physical properties of various functional materials, whereas SCAPS (version. 3.3.07) patterns the photovoltaic metrics including the fill factor (FF), power conversion efficiency (PCE), open-circuit voltage (Voc), short-circuit current density (Jsc), maximum voltage (Vm), maximum current (Im), absorption and reflection coefficients, and energy state diagram of the whole device. Alternation of illumination power and use of different buffer materials was utilized as the main tuning strategy. The champion layout was achieved by optimization of the stacking model, material system, and power of illumination, which demonstrated 26.32% PCE, 83.77% FF, Jsc of 26.27  mA  /  cm², and the exceptional Voc of 1.19 V. This theoretical performance remains stable in 1000  W  /  m² light radiation. The calculated efficiency and FF were very close to the previously reported experimental data, and this proved the high accuracy of this simulation work. These findings promise a feasible application of PSC in high-efficiency wearable electronics.