Heavily phosphorus-doped nano-crystalline diamond electrode for thermionic emission application

Kato, Hiromitsu; Takeuchi, Daisuke; Ogura, Masahiko; Yamada, Takatoshi; Kataoka, Mitsuhiro; Kimura, Yuji; Sobue, Susumu; Nebel, Christoph E.; Yamasaki, Satoshi

doi:10.1016/j.diamond.2015.08.002

Cited by 31 publications

(24 citation statements)

References 19 publications

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“…During the growth, the CH 4 /H 2 flow ratio was kept at 1 %, while the P/C ratio was 2. The phosphorus concentration in the doped diamond film, estimated using secondary ion mass spectrometry in the same way as reported, was 5×10 20 cm −3 . As‐grown P‐NCD films were further annealed in a thermal chemical vapor deposition device.…”

Section: Methodsmentioning

confidence: 92%

“…The P‐NCD films were grown on molybdenum substrates by a plasma‐enhanced chemical vapor deposition (CVD) technique . Prior to film deposition, the molybdenum substrate was seeded with a nano‐diamond (diameter: 3–6 nm) colloidal solution using a sonic wave bath.…”

Section: Methodsmentioning

confidence: 99%

“…In this work, electrochemical properties of heavily phosphorus‐doped nanocrystalline diamond (P‐NCD) films with a doping level over 10 20 cm −3 , grown using a MWCVD technique, were investigated. To attain P‐NCD films with enhanced electrical conductivity, annealing treatment of as‐grown P‐NCD films was carried out in vacuum for hours.…”

Section: Introductionmentioning

confidence: 99%

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Phosphorus‐Doped Nanocrystalline Diamond for Supercapacitor Application

Kato

et al. 2018

ChemElectroChem

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Heavily phosphorus-doped nanocrystalline diamond (P-NCD) has been grown by using a plasma-enhanced chemical vapor deposition technique and further applied as an electrode for the construction of supercapacitors. This P-NCD electrode shows a capacitance of 11.40 μF cm À 2 in 1.0 M Na 2 SO 4 at a scan rate of 10 mV s À 1 and behaves as a n-type semiconductor electrode in redox-active electrolyte of 0.05 M Fe(CN) 6 3À /4À + 1.0 M Na 2 SO 4 . The post-thermal treatment of as-grown P-NCD films in vacuum at high temperatures for several hours leads to the achievement of much higher capacitances. At the scan rates of 10 and 20 mV s À 1 , the capacitances are up to 2.01 and 63.56 mF cm À 2 for an electrical double layer capacitor and a pseudocapacitor, respectively. Such high capacitances originate from the improved electrical conductivity, varied surface state and surface functional groups, and changed content of noncarbon diamond inside the P-NCD films during the annealing treatment. Therefore, P-NCD films are quite promising as an electrode material for supercapacitor applications.[a] Dr.Electrochemical measurements were carried out on a CHI660E Potentiostat/Galvanostat (Shanghai Chenhua Inc., China) using a standard three-electrode cell, where the P-NCD film acted as the working electrode, an Ag/AgCl (3 M KCl) as the reference electrode, and a coiled Pt wire as the counter electrode. The effective area of the working electrode that exposed to the electrolyte was a circular area of approximately 0.05 cm À 2 . For the construction of diamond EDLCs and PCs, 1.0 M Na 2 SO 4 and 1.0 M Na 2 SO 4 containing 0.05 M K 3 Fe(CN) 6 /K 4 Fe(CN) 6 aqueous solutions were utilized, respectively. Their performance was examined using cyclic voltammetry at different scan rates, the galvanostatic charging/discharging method at different current densities, and electrochemical impedance spectroscopy technique at open circuit potentials in the frequency range of 0.01 to 10 6 Hz.

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Section: Methodsmentioning

confidence: 92%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Phosphorus‐Doped Nanocrystalline Diamond for Supercapacitor Application

Kato

et al. 2018

ChemElectroChem

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“…Moreover, the field emission characterization of a heavily P-doped H-terminated diamond (111) surface resulted in a P donor level~0.6 eV below the VBM [12]. A donor level at 2.3 eV below VBM was also observed for NCD [13]. Furthermore, the novel Q-carbon phase shows an outstanding electron emission property.…”

mentioning

confidence: 93%

The Combined Influence of Dopant Species and Surface Termination on the Electronic Properties of Diamond Surfaces

Larsson

2020

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The combined effects of geometrical structure and chemical composition on the diamond surface electronic structures have been investigated in the present study by using high-level theoretical calculations. The effects of diamond surface planes [(111) vs. (100)], surface terminations (H, F, OH, Oontop, Obridge, vs. NH2), and substitutional doping (B, N vs. P), were of the largest interest to study. As a measure of different electronic structures, the bandgaps, work functions, and electron affinities have been used. In addition to the effects by the doping elements, the different diamond surface planes [(111) vs. (100)] were also observed to cause large differences in the electronic structures. With few exceptions, this was also the case for the surface termination species. For example, Oontop-termination was found to induce surface electron conductivities for all systems in the present study (except for a non-doped (100) surface). The other types of surface terminating species induced a reduction in bandgap values. The calculated bandgap ranges for the (111) surface were 3.4–5.7 (non-doping), and 0.9–5.3 (B-doping). For the (100) surface, the ranges were 0.9–5.3 (undoping) and 3.2–4.3 (B-doping). For almost all systems in the present investigation, it was found that photo-induced electron emission cannot take place. The only exception is the non-doped NH2-terminated diamond (111) surface, for which a direct photo-induced electron emission is possible.

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“…This makes phosphorusdoped diamond more promising for device applications, e.g. as an electron source for bipolar devices [13][14][15], as Schottky barrier diodes, and for thermionic emission applications [16,17]. Surface termination is the general notation when a surface-binding species is used to uphold the cubic structure, or to change the surface properties of diamond.…”

Section: Introductionmentioning

confidence: 99%

A Theoretical Study of the Energetic Stability and Electronic Structure of Terminated and P-Doped Diamond (100)-2x1 Surfaces

2019

ANN

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The combined effect of P-doping and surface-termination on the energetics, and especially the electronic structure, of a diamond (100) surface, has in the present study been investigated by using a Density Functional Theory method. The diamond surface was terminated with any of the following species: H, F, OH, Obridge and NH2 . These adsorbates have earlier experimentally been proven crucial for e.g. applications based on surface electrochemistry. The observed results were analysed with the purpose to obtain a deeper knowledge about the atomic-level cause to the observed effects by the P doping and surface termination. The P dopant was found to have a very minor influence on the averaged adsorption energy for the various terminating species (i.e. with less than 0.17 eV). Moreover, the adsorbates were found to reduce the stability of the P-dopant in the diamond lattice. When analysing the results of the calculated partial density of states, the P dopant was found to contribute with band gap states below the conduction band, out of which one is a donor band. In addition, the surfaces with their terminating species will contribute with empty band gap states just below the CBM of the diamond surfaces. Hence, the combination of P doping and surface termination will induce both donor and acceptor states in the diamond surface band gap, which will improve the usefulness of these specific diamond surfaces in various electronic devices. The work function of a diamond surface is one specific properties that will be affected by substitutional doping and surface termination. Within the present study, the terminating species were found to render a strong impact on the surface work function (as compared to a non-terminated diamond (100)-2x1 surface), with calculated work function values that were even further decreased by P-doping.

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Heavily phosphorus-doped nano-crystalline diamond electrode for thermionic emission application

Cited by 31 publications

References 19 publications

Phosphorus‐Doped Nanocrystalline Diamond for Supercapacitor Application

Phosphorus‐Doped Nanocrystalline Diamond for Supercapacitor Application

The Combined Influence of Dopant Species and Surface Termination on the Electronic Properties of Diamond Surfaces

A Theoretical Study of the Energetic Stability and Electronic Structure of Terminated and P-Doped Diamond (100)-2x1 Surfaces

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