Abstract <p>In order to address the issues of fossil energy shortage and environmental pollution, developing efficient solar photovoltaic technology is particularly important. InGaN-based solar cells have wide application potential in photovoltaic fields such as space solar power stations due to their tunable bandgap, strong radiation resistance, and high-temperature tolerance. However, the power conversion efficiency is affected by factors such as In content, doping concentration, and the type and thickness of the intrinsic layer. In this study, we have investigated the effects of In content, doping concentration and thickness of <i>i</i>-layer on the properties of <i>p</i>–<i>n</i> and <i>p</i>–<i>i</i>–<i>n</i> InGaN-based solar cells with different <i>i</i>-layers (InGaN layer and GaN layer) using a numerical simulation method. We extracted the performance parameters of InGaN-based solar cells through <i>I</i>–<i>V</i> curves, such as <i>I</i>_sc, <i>V</i>_oc, FF, PCE and ideality factor, conclusions indicate that the <i>p</i>–<i>n</i> junction is optimized under ideal condition with an In content of 0.3 and doping concentrations of 1 × 10¹⁸/cm³ and 1 × 10¹⁷/cm³, and we obtained the ideal power conversion efficiency of 44.45%. The <i>p</i>–<i>i</i>–<i>n</i> structure is further investigated using InGaN and GaN as the <i>i</i>‑layer, each with a thickness of 2.0 μm, and the power conversion efficiency reaches 57.47%, which is mainly attributed to the enhanced built‑in electric field and carrier separation efficiency resulting from the strong polarization effect of GaN. This study provides a theoretical basis for the device design and performance optimization of InGaN-based solar cells.</p>