An insight into the mechanism of surface conductivity in thin film diamond

Looi, Hui Jin; Pang, Lisa Y.S.; Molloy, A.B.; Jones, F.H.; Foord, John S.; Jackman, Richard B.

doi:10.1016/s0925-9635(97)00252-5

Cited by 70 publications

(21 citation statements)

References 18 publications

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“…In cases where response loss is observed, diamond electrodes can often be reactivated by isopropanol cleaning or by hydrogen plasma treatment. The latter pretreatment (i) cleans the surface, (ii) replaces the surface oxygen termination ( e.g ., C-OH, C=O and C-O-C functionalities) with a hydrogen termination and (iii) adds subsurface hydrogen that increases the surface conductivity through an elevation in the carrier concentration (18,19). Given the fact that a microwave reactor for the hydrogen plasma treatment is not available to most users, work is needed to identify appropriate pretreatment methods that function to reactivate diamond electrodes and are convenient to apply.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical activation of diamond microelectrodes: implications for the in vitro measurement of serotonin in the bowel

Durán

Brocenschi

Galligan

et al. 2014

Analyst

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The electrochemical pretreatment of diamond microelectrodes was investigated for the purpose of learning how an anodic, cathodic or a combined anodic + cathodic polarization affects the charge-transfer kinetics for two surface-sensitive redox systems: ferri/ferrocyanide and serotonin (5-hydroxytryptamine, 5-HT). The pretreatments were performed in 0.5 mol L−1 H2SO4. The anodic pretreatment was performed galvanically for 30 s at 250 mA cm−2. The 10 cathodic pretreatment was performed for 180 s at −250 mA cm−2. The combined pretreatment involved application of the anodic step first followed by the cathodic step. The results clearly demonstrate that the best performance for both redox systems is obtained after the cathodic polarization, which presumably activates the electrode by cleaning the surface and removing site-blocking surface carbon-oxygen functionalities. The cathodic pretreatment was found to be effective at activating a fouled microelectrode in situ. This observation has important implication for the measurement of 5-HT in the bowel.

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Section: Introductionmentioning

confidence: 99%

Electrochemical activation of diamond microelectrodes: implications for the in vitro measurement of serotonin in the bowel

Durán

Brocenschi

Galligan

et al. 2014

Analyst

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“…Whilst the origin of these carriers remains controversial, our recent studies suggest that the interaction of hydrogen with defects within the near surface region of CVD material leads to the formation of very shallow acceptor states. 7 This approach to doping thin film polycrystalline diamond has been successfully used to produce highly effective field effect transistors. 8 In this letter we report low temperature Hall effect measurements performed on a number of differing types of CVD diamond, each of which has been subjected to a hydrogenation process.…”

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confidence: 99%

Formation of shallow acceptor states in the surface region of thin film diamond

Williams

Whitfield

Jackman

et al. 2001

Applied Physics Letters

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Considerable interest exists in fabrication of electronic devices from thin film polycrystalline diamond. To date, doping this material to achieve good free carrier concentrations and mobilities at room temperature has proved difficult. In this letter we report low temperature Hall effect measurements made on diamond films subjected to a hydrogenation process, such that the near surface region becomes p type without the addition of conventional dopant atoms. High carrier concentrations and mobilities can be achieved. The change in carrier concentration within the temperature range 10–300 K does not change as expected for most films, actually increasing as the temperature falls. This effect could be related to the confinement of carriers at the surface caused by the dipole provoked by adsorbed hydrogen on the diamond. However, polished films display more conventional behavior in that the carrier concentration falls with falling temperature.

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“…For this reason, it was proposed that hydrogen at the diamond surface promotes the formation of gap states which act as shallow acceptors leading to p-type diamond. 2,3 In our laboratory, it has been observed that the surface conductivity of hydrogen-terminated diamond decreases slightly after the sample is put into vacuum. But much more dramatically dropped the conductivity after the sample had been annealed in vacuum to 572 K and then cooled down to 294 K. The resulted change in resistance was several orders of magnitude.…”

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confidence: 99%

Influence of adsorbates on the surface conductivity of chemical vapor deposition diamond

Szameitat

Jiang

Beyer

2000

Applied Physics Letters

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To investigate the mechanism of the diamond surface conductivity, temper experiments have been performed on chemical-vapor-deposited (CVD) diamond films under vacuum conditions. The surface conductivity of these films was measured as a function of temperature and in contact with different gas atmospheres. These results were compared with those obtained by gas evolution experiments performed on CVD diamond samples of the same kind, demonstrating the possible role of CO adsorption to the surface conductivity

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An insight into the mechanism of surface conductivity in thin film diamond

Cited by 70 publications

References 18 publications

Electrochemical activation of diamond microelectrodes: implications for the in vitro measurement of serotonin in the bowel

Electrochemical activation of diamond microelectrodes: implications for the in vitro measurement of serotonin in the bowel

Formation of shallow acceptor states in the surface region of thin film diamond

Influence of adsorbates on the surface conductivity of chemical vapor deposition diamond

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