Ion Beam-Induced modification in the optical properties of the bilayer of nano-structured amorphous selenium and multi-walled carbon Nanotubes: A study by 70 MeV Ni Ions

Abstract

In this study, we report improved physical properties of selenium with multi-walled carbon nanotubes (MWCNTs) resulting from a homogeneous mixture of CNT-Se bi-layer thin film by using swift heavy ion irradiation. FESEM micrographs clearly showed the inter-diffusion of Se nanoparticles into MWCNTs following swift heavy ion (SHI) irradiation, EDX validates the elemental composition. The existence of different phonon modes (LO mode and D, G, G' bands) has been found in the Raman spectra of the investigated bi-layer thin films. UV–Visible spectroscopic analysis of pristine CNT-Se thin films show two sharp absorption edges at ∼670 nm and ∼340 nm. After swift heavy ion irradiation, the sharp absorption edge at ∼670 nm exhibits a blue shift, whereas the absorption edge at ∼340 nm exhibits a red shift, confirming the homogeneous mixing of two layers. These remarkable shifts found in the optical properties of CNT-Se bi-layer make the investigated material feasible for many optoelectronic device applications.