This study investigates the electrochemical nucleation and growth mechanisms of bismuth on a monocrystalline n‐Si(111) substrate from an acidic nitrate solution. It also examines the electrical and optical properties of the electroplated films. The qualitative analysis of the experimental current transients reveals a strong agreement with instantaneous nucleation on active sites and three‐dimensional diffusion‐controlled growth. Electrochemical kinetic parameters are derived using the Mirkin–Nilov–Heerman–Tarallo model, which is employed to fit the experimental curves. Electrochemical impedance spectroscopy and Mott–Schottky analysis are used to assess the electronic characteristics of the materials. Scanning electron microscope observations show a uniform, smooth, and continuous deposit. X‐ray diffraction analysis indicates a high texture along the [012] direction of the rhombohedral crystal structure in thin bismuth films with different thicknesses (118, 318, and 611 nm). UV–visible spectroscopy is employed to investigate the optical characteristics of the Bi/Si surface in the 200–1100 nm wavelength range. The study demonstrates that the thickness of the bismuth film affects the absorption response of the Bi/Si heterojunction, showing a notable increase in absorption in the visible and infrared ranges. Furthermore, it is found that the photoluminescence properties of the Bi/Si heterojunction are improved in the visible and infrared ranges.