Impact of the Silicon Nitride Nanoparticles (Si3N4 NPs) on the Optical Properties of Carboxymethyl Cellulose (CMC) for solar cell applications

In this study, CMC/Si3N4 nanocomposite films were effectively made utilizing the casting method with various Si3N4 nanoparticle loadings for possible solar cell applications.The optical characterization demonstrated that adding Si3N4 nanoparticles considerably improves the optical performance of the CMC matrix.An increase in nanoparticle concentration resulted in increased absorbance and lower transmittance, indicating better light harvesting capability.The optical band gap decreased with increasing Si3N4 content, with the greatest reduction occurring at 4.2 wt.%, indicating the creation of localized energy states and improved electronic interactions within the polymer matrix.Furthermore, important optical metrics such as absorption coefficient, refractive index, extinction coefficient, dielectric constants, and optical conductivity demonstrated a steady rise with nanoparticle loading.These results demonstrate that Si3N4 nanoparticles play a crucial role in tuning the optical properties of CMC, making the developed nanocomposites promising candidates for optoelectronic and solar cell applications.