Optical Properties of Single‐Walled Carbon Nanotubes Doped in Acid Medium

Abstract

We report a detailed study of changes in optical properties of single-walled carbon nanotubes caused by doping in acid medium and their comparison with those induced by other doping techniques. In this work, a hydrochloric acid was added to the aqueous suspension of nanotubes wrapped with sodium cholate. Additionally to the shift and suppression of several modes in the Raman spectrum and the suppression of the first optical transition in the optical absorption spectrum, we have observed an appearance of a trion band in the photoluminescence spectrum with the energy about 0.2 eV less than the main photoluminescence band.

Many-particle excitations in non-covalently doped single-walled carbon nanotubes

“…Since we do not observe a rise of the “defective” D-mode in the Raman spectra with HCl added (see Fig. 2), we reject the hypothesis of defect-localized excitonic states 12 . However, both theoretical 21 and experimental 22 studies have shown that excitons may localize due to the impact of ions adsorbed on the surface of SWNTs, even without covalent bonds.…”

“…The rise of trion-to-exciton band intensity rate in the photoluminescence spectra with increasing the doping level was reported by several groups [5][6][7][8][9]. Under the high level of doping the intensity of the trion band reached the intensity of the exciton band or even slightly exceed it [10].…”

Кислородные Дефекты В Одностенных Углеродных Нанотрубках Для Источников Излучения В Ближнем Инфракрасном Диапазоне

“…Действительно, влияние локальной окружающей среды на экситонную люминесценцию недопированных ОУНТ достаточно подробно исследовано [41][42][43][44]. В частности, установлено, что яркость фотолюминесценции ОУНТ достаточно сильно зависит от кислотности окружающей среды [45,46]. Перспективность ОУНТ с внедренными нульмерными квантовыми дефектами в качестве источника света в ближнем ИК диапазоне делает актуальным вопрос о чувствительности нульмерных экситонов к локальной окружающей среде, в частности, к кислотности среды.…”

Nanocarbon Photonics and Optoelectronics

“…The productive discussions during the meeting (which has been held on 19–24 March 2017) were provided by perfect organization and nice natural environment, including ski slopes, at Krasnaya Polyana resort (Sochi, Russia). The contributions (in total an amount of 30) of this Special Issue are covering research work related to production, characterization and application of the nanocarbon materials which include diamonds, carbon nanotubes, graphene other types of nanocarbon materials, and their composites . Traditionally for the NPO Workshop series there is also some portion of reports devoted to non‐carbon materials demonstrating properties and phenomena analogous to those observed for nanocarbons.…”

“…Most of the structural and other properties of carbon nanomaterials may be efficiently evaluated using traditional analytical techniques, such as XPS, Raman, electron microscopy, optical spectroscopy, etc. The papers presented in this Special Issue demonstrate also characterization of electrochemical, electromagnetic, and thermal properties of graphenic carbon structures.…”