In our study, we examined the growth of SiO2-aminopropyltriethoxysilane nanoparticles decorated with carbon nanotubes (CNTs) on a chitosan matrix. This matrix was synthesized through a sol-gel process, where chitosan was dissolved into a silicate sol and subsequently gelled at 50 °C. To explore the structure, morphology, and optical properties of these semiconductor nanocomposites, we employed various analytical techniques including X-ray diffraction (XRD), transmission electron microscopy (SEM), Fourier Transform Infrared (FT-IR) spectroscopy, and UV-vis spectroscopy. From the UV-Vis spectroscopy measurements, the absorption, band gap, refractive index, and optical conductivity were extracted and analyzed with respect to the incident wavelength and content of CNTs. The incorporation of CNTs into the chitosan-SiO2-aminopropyltriethoxysilane semiconductor nanocomposite results in enhanced crystallinity, increased surface area, and modified optical properties. Therefore, it can be inferred that the optical characteristics of the chitosan-SiO2-aminopropyltriethoxysilane composite are significantly influenced by the ratio of CNT decoration.