Semnan University Press Progress in Physics of Applied Materials 2783-4794 6 4 2026 12 01 Impact of Thickness and Doping Concentration on Heterojunction InP/Si-Based Solar Cell Performance: Insights from PC1D and Wafer Ray Tracer Simulations 285 291 10587 10.22075/ppam.2026.40162.1197 EN Nur Ain Syazliin Mohamed Azman School of Physics and Material Studies, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia Mohd Zaki Mohd Yusoff Institute for Biodiversity and Sustainable Development (IBSD), Universiti Teknologi MARA, 40450 Shah Alam, Malaysia Madhiyah Yahaya Bermakai Institute of Sciences (IOS), Universiti Teknologi MARA, 40450 Shah Alam, Malaysia 0000-0003-1916-6505 Rosalio G. Artes Jr. Faculty of Applied Science, Universiti Teknologi MARA, Perlis Branch, 02600 Arau, Malaysia Jeffrey Imer C. Salim Mindanao State University Tawi-Tawi College of Technology and Oceanography, Philippines Journal Article 2025 12 24 The study aimed to investigate how different doping concentrations and n-region layer thicknesses affected the efficiency of InP/p-Si solar cells. The n- and p-regions were represented by indium phosphide (InP) and silicon (Si), respectively, with band gaps of 1.35 eV and 1.124 eV. To optimize the efficiency and performance of InP/p-Si solar cells, the study systematically varied the doping concentrations over six orders of magnitude, ranging from 1×10¹⁴ cm⁻³ to 1×10¹⁷ cm⁻³, and adjusted the thickness of the n-region layer from 5μm to 30 μm. Reflection, absorption, and transmission characteristics of heterojunction InP/Si layers in the wavelength region of 300-1200 nm were also modelled by wafer ray tracer software. At 450-700 nm wavelength, 50 nm InP sample exhibited minimum reflection compared to all other samples. Trends showed that the absorption decreased with increasing thickness of InP layer between 300 and 920 nm. The data obtained from the absorption measurement at different thicknesses was in agreement with the data obtained from the result of impact of different n-region thickness of InP/p-Si solar cells, where the reduction in InP layer thickness resulted in the increase of absorption, which in turn increased the current due to the higher absorption of photons and the generation of excess electron carriers. https://ppam.semnan.ac.ir/article_10587_950e96d118e30aef0c89b7721fe07ab7.pdf