Near infrared (NIR) light is useful for advanced applications including bio-imaging/sensing and telecommunications. As an alternative to conventional NIR materials including rare earth-containing inorganic crystals, carbon nanotubes (CNTs) are promising candidates due to their NIR emission properties. However, the low emission efficiency and the structure-dependent emission wavelength of the pristine CNTs limit the application fields. In this research, we found that bis-functional chemical modifiers create new NIR emission from the chemically-modified CNTs.
Nakashima says “The new emission has not been observed in conventional systems and is much larger red-shifted than those of pristine CNTs and the previously-reported chemically-modified CNTs”. Shiraki says “Our method can achieve NIR emission wavelength design based on chemical structures of the modifiers even if we use same CNTs as raw materials”.
The research achievement was published online in Scientific Reports on 27th June, 2016.
Fig. 1. Schematic diagram of the new chemically-modified CNT that was developed in this study.
Fig. 2. Chemical structure of the synthesized bis-functional modifier and photoluminescence spectra of our chemically-modified CNT (red line), pristine CNT (black line), and previously-reported chemically-modified CNT (blue line). The new emission is highlighted by a reddish region.
Title: Emergence of new red-shifted carbon nanotube photoluminescence based on proximal doped-site design
Authors: Tomohiro Shiraki, Tomonari Shiraishi, Gergely Juhász & Naotoshi Nakashima