Enhanced exciton photoluminescence in carbon nanotubes

Abstract

Carbon nanotubes are quasi-one-dimensional (1D) quantum wires that exhibit near infrared luminescence, and their emission wavelengths are suitable for photonic applications in telecommunication and bio-imaging technology. However, their relatively low luminescence quantum yield (typically ~1%) has hindered such applications of carbon nanotubes. Here we discuss enhancement phenomena of exciton luminescence in zero-dimension (0D)-like local states sparsely embedded in quasi-1D carbon nanotubes. It has been found that the luminescence quantum yield of the excitons confined in the 0D-like states can be more than at least one order larger (~18%) than that of the intrinsic 1D free excitons. These results will pave the way for carbon-based photonics without relying on conventional compound semiconductors made of minor metals.