A detailed balance model has been extended to calculate the performance of Cs3Sb2Br9-based “planar” and “textured” perovskite solar cells (PSCs) having a back absorbing substrate at the rear side and an angular restriction layer at the front side of the active layer. The influence of unit step and continuously varying absorptivity on the cell’s performance is observed by varying the thickness of the active layer. The obtained maximum performance, such as open-circuit voltage (VOC), short-circuit current (JSC), and power conversion efficiency (PCE) at an optimum thickness of 1000 nm, without considering angular restriction layer, is 1.70 V, 14.48 mAcm−2, and 22.72%, respectively. When an angular restriction layer is applied, the PCE relative increases by more than 5.67% for lower angle (θ = 10◦) in Cs3Sb2Br9-based “textured” PSC. Considering the existence of photon recycling effect (PRE), the influence of nonradiative recombination mechanism with radiative recombination mechanism is also observed by the ratio of radiative and nonradiative lifetime fraction (γ). We observe that for the active layer’s PRE, γ should be less than 0.3. Finally, the influence of r(λ,θ) is observed and also compared with 1-D simulation for a practical PSC. Thus, for “planar” Cs3Sb2Br9-based PSC, the limit of PCE is 24.01% having a back absorbing substrate at rear side and an angular restriction layer at the front side. The assumption of PRE in perovskite cell is also observed with a comparison of extended detailed balance model with the standard Shockley model and 1-D simulation.