Abstarct: Silicon carbide (SiC) nanoparticles are considered promising materials for optical and optoelectronic systems due to their wide band gap, high chemical and thermal stability, and the tunability of their electronic and optical properties. Nevertheless, the simultaneous control of phase purity, microstructure, and optical response remains one of the major challenges in the nanoscale synthesis of this material. In the present study, alloyed SiC nanoparticles were synthesized via the sol-gel method followed by carbothermal reduction, and the effects of key processing parameters-including precursor type, carbon-to-silicon ratio, thermal treatment conditions, and the type and concentration of alloying elements-on the structural and optical properties of the samples were systematically investigated. The results indicated that precursor homogeneity and precise control of the chemical conditions during the sol–gel stage play a fundamental role in completing the carbothermal reaction and increasing the fraction of the SiC phase. Furthermore, increasing the final annealing temperature led to improved crystallinity, enhanced crystallite growth, and a reduction in undesirable residual phases. Analysis of the C/Si stoichiometric ratio also demonstrated that optimal SiC formation occurs only within a specific compositional range; deviations from this optimal ratio can reduce the reaction yield and result in the persistence of silica phases or the presence of free carbon. Moreover, controlled alloying induced local lattice modifications and band structure adjustments, thereby tuning the intensity and position of optical emission. However, excessive dopant concentrations were associated with reduced crystallinity and an increased density of nonradiative recombination centers. These findings indicate that the optical performance of SiC nanoparticles is strongly governed by the interplay between synthesis conditions, chemical composition, and the degree of alloying. Therefore, the simultaneous optimization of these parameters can provide an effective pathway for designing SiC nanostructures with tunable properties and enhanced performance for optical and optoelectronic applications. In this study, alloyed silicon carbide nanoparticles were synthesized to evaluate their potential for optical applications, and their phase structure, chemical bonding, and crystallinity were investigated. The samples were synthesized under different thermal treatment conditions at three temperatures 900, 1200, and 1450 °C for 3 hours. X-ray diffraction results showed that the sample annealed at 900 °C, labeled M17, was predominantly amorphous, indicating that the formation of the desired phase was incomplete at this temperature. Additionally, the presence of minor peaks at diffraction angles of 20.9°, 23.5°, 30.2°, and 54.9° suggested the existence of small amounts of secondary phases or impurities in some samples. Fourier transform infrared (FTIR) spectroscopy revealed that in sample M18, absorption bands at 480 and 1080 cm⁻¹ together with a weak peak near 815 cm⁻¹ were observed, indicating the dominance of silica-related phases and limited formation of silicon carbide. In sample M19, the appearance of a peak at 820 cm⁻¹ along with the bands at 480 and 1080 cm⁻¹ indicated further progress of the reaction and improved formation of the SiC phase. In sample M20, which was synthesized using 2 g of sucrose as the carbon source, a distinct peak around 610 cm⁻¹ was detected, and this sample was identified as the optimal composition. Additional FTIR data confirmed the presence of bands at 1375, 1450, and 1632 cm⁻¹. Raman spectroscopy of sample M20 revealed transverse optical (TO) and longitudinal optical (LO) modes in the ranges of 770–795 cm⁻¹ and 940–980 cm⁻¹, respectively. These modes exhibited the highest intensity and the narrowest linewidths, indicating superior structural crystallinity in this sample. Overall, the results demonstrate that increasing the annealing temperature and carefully controlling the carbon source content play a decisive role in improving crystallinity, reducing undesirable phases, and achieving silicon carbide nanoparticles with structural properties suitable for optical applications.