Unusual surface and edge morphologies, sp2 to sp3 hybridized transformation and electronic damage after Ar+ ion irradiation of few-layer graphene surfaces

Abstract

Roughness and defects induced on few-layer graphene (FLG) irradiated by Ar+ ions at different energies were investigated using X-ray photoemission spectroscopy (XPS) and atomic force microscopy techniques. The results provide direct experimental evidence of ripple formation, sp2 to sp3 hybridized carbon transformation, electronic damage, Ar+ implantation, unusual defects and edge reconstructions in FLG, which depend on the irradiation energy. In addition, shadowing effects similar to those found in oblique-angle growth of thin films were seen. Reliable quantification of the transition from the sp2-bonding to sp3-hybridized state as a result of Ar+ ion irradiation is achieved from the deconvolution of the XPS C (1s) peak. Although the ion irradiation effect is demonstrated through the shape of the derivative of the Auger transition C KVV spectra, we show that the D parameter values obtained from these spectra which are normally used in the literature fail to account for the sp2 to sp3 hybridization transition. In contrast to what is known, it is revealed that using ion irradiation at large FLG sample tilt angles can lead to edge reconstructions. Furthermore, FLG irradiation by low energy of 0.25 keV can be a plausible way of peeling graphene layers without the need of Joule heating reported previously.

Surface modification of multilayer graphene using Ga ion irradiation

“…31,33,34 The increase of the surface topography can also be attributed to the ripple structure, which is known to form on the surface of graphene after ion irradiation. 35,36 The adhesion between the AFM tip and multilayer graphene was found to increase following Ga ion irradiation, as determined using the peak force tapping mode at ambient temperature. The MESP probe, a model of magnetic probe, was used.…”

Application of the Taguchi Method to Optimize Graphene Coatings on Copper Nanoparticles Formed Using a Solid Carbon Source

“…Graphene can prevent not only oxidation from air 14,15) , but also its large electrical and thermal conductivities make it suitable for applications in electronic devices 16,17) . However, graphene is prone to structural defects due to the adsorption of contaminants onto its surface and breaking of the hexagonal bonding structure, which reduces the electrical conductivity, especially with very thin layers of graphene [17][18][19][20] . A source of carbon is required to form graphene.…”

The change in electronic structure of oriented multilayer carbon nanotubes under action of pulsed ion beam of nanosecond duration

“…Многие физико-химические свойства подобных структур в значительной степени зависят от химического со-стояния поверхностных атомов. Использование по-верхностно чувствительных рентгеноэлектронных методов XAES (X-ray Auger Electron Spectroscopy) и XPS (X-ray Photoelectron Spectroscopy) позволяет провести химический анализ атомов в приповерх-ностной области данных структур [2][3][4]. Анализ первой производной оже-спектра C KVV методом XAES позволяет получить количественную инфор-мацию о доле атомов углерода в sp 2 -и sp 3 -гибри-дизации.…”

“…Использование по-верхностно чувствительных рентгеноэлектронных методов XAES (X-ray Auger Electron Spectroscopy) и XPS (X-ray Photoelectron Spectroscopy) позволяет провести химический анализ атомов в приповерх-ностной области данных структур [2][3][4]. Анализ первой производной оже-спектра C KVV методом XAES позволяет получить количественную инфор-мацию о доле атомов углерода в sp 2 -и sp 3 -гибри-дизации. Ценную информацию о распределении плотности занятых электронных состояний вблизи уровня Ферми также можно получить из анали-за спектров электронов валентной зоны.…”

“…Таким образом, установлено, что увеличение доли атомов углерода в sp 3 -гибридизации в поверхностных слоях нано-трубок обусловлено, в частности, ионно-стимулиро-ванным образованием тонких МУНТ, формирова-нием структур, состоящих из инкапсулированных кластеров железа в графитовой оболочке, а также образованием углерода луковичной формы.…”