Using electroless etching, the optical and electrical properties of conical silicon nanowires were fabricated and studied

Silicon nanowires (SiNWs) were fabricated by electroless etching of n-type Si (100) wafer in HF/AgNO ₃ . High-density, vertically stacked silicon nanowires are formed on silicon substrates. Different shapes of silicon nanowires are observed. The maximum recorded reflectance of silicon nanowires is about 19.2%, which is much lower than that of silicon substrate (65.1%). Through the results, in the near-ultraviolet region, the minimum reflection reaches about 3.5%, while in the visible infrared region it reaches 9.8%. It was also found that the calculated band gap energy of silicon nanowires is slightly higher than the energy of the silicon substrate. The I–V characteristics of the independent silicon nanowires exhibit a linear ohmic behavior for forward bias. The average resistance of silicon nanowires is about 12.9 Ω cm. Using experimental reflectance spectra, the optical properties of different types of conical silicon nanowires (SiNWs) were investigated and the effective refractive index (n) was obtained for both the conical silicon nanowire samples and the silicon nanowire group. Under AM 1.5G illumination, the device exhibits a short circuit current density (J _sc ) of 13.4 mA/cm ² , an open circuit voltage (V _oc ) of 0.479 V and a fill factor (FF) of 43.4%, giving a power conversion efficiency of 2.89%. The observed J _sc is higher than that of the control device with planar Si p-n junction, indicating a significant improvement in carrier generation and collection efficiency of the palanr structure. The effect of series resistance (Rs) was also studied.