Determination of Carrier Densities of Boron- and Nitrogen-Doped Multiwalled Carbon Nanotubes Using Mott–Schottky Plots

Abstract

Knowledge of the carrier type (p- or n-type) and the carrier density of carbon nanotubes is critical in semiconductor applications such as thermoelectric power generation and Peltier cooling. In this paper, an experimental procedure for electrochemically characterizing multiwalled carbon nanotubes (MWCNTs) doped with boron or nitrogen has been presented. The carrier type and carrier density of the doped MWCNTs were determined by generating Mott–Schottky plots. The boron-doped nanotubes were synthesized using the substitution reaction method and the nitrogen-doped MWCNTs were synthesized using the continuous-feed chemical vapor deposition (CVD) method using pyridine or acetonitrile as the carbon precursor and ferrocene as the metal catalyst particle precursor. The nitrogen-doped nanotubes were synthesized at different CVD reaction temperatures: 650, 700, 800, and 900°C , and the effect of reaction temperature on the carrier densities of the carbon nanotubes was examined. Thermoelectric devices were constructed using pyridine nanotubes synthesized at different synthesis temperatures, and it was found that with any change (increase/decrease) in the carrier densities reflected a corresponding change in the thermoelectric power of the nanotubes.

Nitrogen-doped carbon nanomaterials: To the mechanism of growth, electrical conductivity and application in catalysis

“…An increase in conductivity of N-CNMs as compared to CNMs was reported in [60,61]. In [60], an increase in the density of states G Model CATTOD-9322; No.…”

“…In [60], an increase in the density of states G Model CATTOD-9322; No. of Pages 11 was established for the N-CNTs synthesized by pyrolysis of acetonitrile or pyridine when the process temperature was raised from 650 to 800 • C and correspondingly amount of nitrogen in N-CNTs increased.…”

One-dimensional nitrogen-containing carbon nanostructures

“…Following after these breakthrough papers, numerous reports regarding preparation of NCNTs by pyrolysis of various N-containing heterocyclic aromatic compounds, solely or in the coordination compounds and the mixtures with other elements/compounds/natural products, were published [39,[67][68][69][70][73][74][75][76]80,89,94,101,105,106,133,141,143,153,154,167,171,172,. Pyrolyses were performed in a broad temperature range 550-1100 °C in an inert (He, N 2 , Ar) or reduction atmosphere (H 2 , Ar/H 2 , Ar/H 2 /NH 3 , H 2 /H 2 O) (Tables [5][6][7][8] in the presence of various catalysts, iron in the form of ferrocene being the most often employed catalyst/catalyst precursor (Tables [5][6][7][8].…”

Chemical Vapor Deposition of Bi-Te-Ni-Fe on Magnesium Oxide Substrate and Its Seebeck Effect

“…The rate of deposition in CVD is typically higher than that in physical vapor deposition (PVD). For example, a high deposition rate was achieved to deposit SrB 6 coating on a sapphire substrate [2]. The obtained SrB 6 coating is n-type.…”

“…CVD carbon based thermoelectric materials such as carbon nanotubes and wires [5][6][7], diamond and diamond-like carbon films [8][9][10][11][12][13] have been extensively studied. Another family of thermoelectric materials made by CVD includes silicon and silicon compound materials, including silicon nanowires [14,15], SiC [16,17], and silicon-based compounds [18][19][20][21].…”