Strong photoluminescence from diameter-modulated single-walled carbon nanotubes

Abstract

Employing the photoluminescence (PL) properties of the semiconducting single-walled carbon nanotubes (SWNTs) in applications is limited by their low quantum yield. Here, we report a simple method for enhancing the efficiency of PL emission by modulating the diameter and hence the bandgap of semiconducting SWNTs along their axes. The PL enhancement is explained by the exciton energy transfer via exciting SWNT segments of large bandgaps which induces emission from the neighboring segments of small bandgaps. The diameter-modulated SWNTs were grown by periodic modulation of the laser beam, and hence, the temperature in a laser assisted chemical vapor deposition process. © 2012 American Institute of Physics.