Effects of Carbon Nanotubes Concentration on Structural and Optical Characteristics of Bismuth Oxide Films

Abstract

Thin films of bismuth oxide (Bi₂O₃) reinforced with carbon nanotubes (CNTs) at different concentrations (1-4 wt.%) were prepared on glass substrates and p-type crystalline silicon with (111) orientation. Nonlinear changes in the crystalline structure were revealed with increasing CNT content, reflecting its complex effect on lattice ordering and phase evolution. Morphological studies showed variable changes in surface roughness, with unit variations at the highest concentration, indicating precise modification in particle distribution and surface structure. Changes in emission intensity were revealed, indicating differential improvement in charge separation and reduction of recombination. Optical analysis showed that the UV–Visible spectrum and the corresponding band gap exhibited nonlinear behavior. These results reflect the complex and nonlinear nature of the CNT effect on the structural, morphological, and optical properties of Bi₂O₃ thin films, offering promising opportunities for precise control of these properties for advanced electronic and optoelectronic applications.