Authors: R. Paul, P. Kumbhakar, A.K. Mitra
Affilation: National Institute Of Technology, India
Pages: 443 - 446
Keywords: modified SWNT, photoluminescence, optical material
Commercially available SWNT of >95% purity was purified by high temperature oxidation and acid treatment. By a simple chemical wet process, SWNT samples were intercalated with as-prepared ZnS nanoparticles. The dried samples were dispersed in DMSO solution and characterized by SEM-EDX, XRD and HRTEM. FTIR study established the presence of sulphur compound with SWNT. HRTEM micrographs revealed the presence of ZnS nanoparticles inside the SWNT bundles. Characteristic UV-Vis-NIR absorbance was observed with a strong absorbance peak at 277 nm. Photoluminescence was studied for a wide range of excitation wavelength from 220 nm to 400 nm. A broad emission in the visible region covering a range upto 650nm with peak emission at 425 nm was observed under UV excitation of 330 nm. Two types of typical emission patterns have been detected, one for 220 nm- 250 nm and another for 260 nm- 400 nm excitation ranges. The characteristics PL emissions as reported in the present article can be explained by considering the modification of the energy band structure of SWNT due to intercalation by the ZnS nanoparticles. The goal of the present work has been to improve and tune the visible luminescence characteristics of SWNT for possible applications in biological imaging, sensors and fabrication of nanoelectronic devices.