High-yield silicon nanowires (SiNWs) were produced on Si substrate by chemical vapor deposition (CVD) method and vapor-liquid-solid (VLS) technique with using SiH4 gas as a precursor. Au thin film with thicknesses of 20 nm deposited on Si (111) substrates were used as catalysts for the growth of nanowires. Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray (EDX), X-ray diffraction (XRD) and Transmission electron microscopy (TEM) were used to characterize the as-synthesized nanowires. The results showed that the SiNWs with uniform growth of nanowires in both directions of diameter and length have a crystalline structure. Increasing the temperature to 600 °C lead to the growth of compacted nanowires. Moreover, reflectance and J-V techniques were performed for optical and electrical measurements. SiNWs arrays surface has low reflectivity (<20%) in the entire spectral range of 400–1100 nm. Performance of two types of samples, namely sample with SiNWs on Si substrate and sample with only polished Si substrate have been compared. It was found that sample with SiNWs on Si substrate has the best optical and electrical properties, resulting suitable for photovoltaic devices.