Near infrared fluorescence and enhanced electrical conductivity of single walled carbon nanotube-lead silicate glass composite

• Enhanced electrical conductivity of SWCNT-Glass composite was observed.
• Activation energy of the composite was found to be reduced appreciably.
• Charge transport properties of the composite were explained with FIT model.
• Broad emission from the composite was found in the NIR wavelength region.
• Fluorescence from SWCNT bundles was discussed with E–E resonance and EET mechanism.

Enhanced electrical conductivity of SWCNT-Lead silicate glass composite was observed in the temperature range of 308 K–473 K. Current–Voltage characteristics of the composite was found to be ohmic in nature, wherein the electrical conductivity was observed to increase significantly with the increase in temperature. Optical properties of the composite through UV-VIS-NIR absorption and NIR fluorescence spectroscopy were ascertained wherein one can observe broad fluorescence between 861 and 1904 nm at room temperature. Micro structural analysis by HRTEM and FESEM shows that single walled carbon nanotubes were randomly distributed inside the glass matrix in the form of bundles. Finally the electrical and optical properties of the composite were explained by fluctuation induced tunneling model, exciton–exciton resonance and excitonic energy transfer.