Ozone Adsorption on Graphene: Ab Initio Study and Experimental Validation

Lee, Geunsik; Lee, Bongki; Kim, Jiyoung; Cho, Kyeongjae

doi:10.1021/jp904321n

Cited by 181 publications

(166 citation statements)

References 33 publications

(80 reference statements)

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“…Ozone molecules ͑O 3 ͒ are expected to preferentially form epoxide groups ͑C u O u C͒ in graphene but other chemical groups can also be created such as C v C, C v O, and C u O. 24 Specifically, we first clean graphene samples by placing them in a flow of Ar/ H 2 gas at 300°C for 3 h. We then expose the samples to ozone in a Novascan ozone chamber, where ozone is produced by ultraviolet irradiation of O 2 gas ͑ϳ7 min, 4 atm͒. The appearance of the D peak in the Raman spectrum ͑Fig.…”

Section: Resultsmentioning

confidence: 99%

Magnetotransport in disordered graphene exposed to ozone: From weak to strong localization

Moser¹,

Tao²,

et al. 2010

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We present a magnetotransport study of graphene samples into which a mild disorder was introduced by exposure to ozone. Unlike the conductivity of pristine graphene, the conductivity of graphene samples exposed to ozone becomes very sensitive to temperature: it decreases by more than three orders of magnitude between 100 and 1 K. By varying either an external gate voltage or temperature, we continuously tune the transport properties from the weak to the strong localization regime. We show that the transition occurs as the phase coherence length becomes comparable to the localization length. We also highlight the important role of disorder-enhanced electron-electron interaction on the resistivity.

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Section: Resultsmentioning

confidence: 99%

Magnetotransport in disordered graphene exposed to ozone: From weak to strong localization

Moser¹,

Tao²,

et al. 2010

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“…[21][22][23] The conductivity of carbon nanotubes (CNTs) was found to increase at low ozone dose or exposure time. 24,25 The proposed mechanism for this increase was the ozone adsorption on the CNT surface, which induces charge transfer effects.…”

Section: Introductionmentioning

confidence: 99%

Probing the electron-phonon coupling in ozone-doped graphene by Raman spectroscopy

et al. 2010

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We have investigated the effects of ozone treatment on graphene by Raman scattering. Sequential ozone short-exposure cycles resulted in increasing the p doping levels as inferred from the blue shift of the 2D and G peak frequencies, without introducing significant disorder. The two-phonon 2D and 2D ′ Raman peak intensities show a significant decrease, while, on the contrary, the one-phonon G Raman peak intensity remains constant for the whole exposure process. The former reflects the dynamics of the photoexcited electrons (holes) and, specifically, the increase of the electron-electron scattering rate with doping. From the ratio of 2D to 2D intensities, which remains constant with doping, we could extract the ratio of electron-phonon coupling parameters. This ratio is found independent on the number of layers up to ten layers. Moreover, the rate of decrease of 2D and 2D ′ intensities with doping was found to slowdown inversely proportional to the number of graphene layers, revealing the increase of the electron-electron collision probability.

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“…Recently, various studies have dealt with the oxidation of graphene by ozone and O ions. [5][6][7][8][9][10][11][12][13][14] In an ozone generator, C atoms are removed from the graphene lattice and vacancies are formed. The morphology of exposed singlelayer and multilayer graphene samples reflects a highly disordered nature, which varies with the thickness.…”

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confidence: 99%