N-Doped Graphene with Low Intrinsic Defect Densities via a Solid Source Doping Technique

Abstract

N-doped graphene with low intrinsic defect densities was obtained by combining a solid source doping technique and chemical vapor deposition (CVD). The solid source for N-doping was embedded into the copper substrate by NH3 plasma immersion. During the treatment, NH3 plasma radicals not only flattened the Cu substrate such that the root-mean-square roughness value gradually decreased from 51.9 nm to 15.5 nm but also enhanced the nitrogen content in the Cu substrate. The smooth surface of copper enables good control of graphene growth and the decoupling of height fluctuations and ripple effects, which compensate for the Coulomb scattering by nitrogen incorporation. On the other hand, the nitrogen atoms on the pre-treated Cu surface enable nitrogen incorporation with low defect densities, causing less damage to the graphene structure during the process. Most incorporated nitrogen atoms are found in the pyrrolic configuration, with the nitrogen fraction ranging from 1.64% to 3.05%, while the samples exhibit low defect densities, as revealed by Raman spectroscopy. In the top-gated graphene transistor measurement, N-doped graphene exhibits n-type behavior, and the obtained carrier mobilities are greater than 1100 cm2·V−1·s−1. In this study, an efficient and minimally damaging n-doping approach was proposed for graphene nanoelectronic applications.

Photo-Induced Doping in a Graphene Field-Effect Transistor with Inkjet-Printed Organic Semiconducting Molecules

“…For the bare graphene, the G peak was found at 1600 cm −1 and the 2D peak at 2700 cm −1 , respectively, whereas for the "PDI on graphene" sample, their locations were at 1592 and 2699 cm −1 . The charges in deposited organic molecules induced doping of graphene, and we observed a clear redshift of the G band up to 8 cm −1 [26] ( Figure 2b). The doping was also confirmed by the broadening of the 2D band of graphene ( Figure 2c) [6].…”

Evaluation of the Environmental Impact and Efficiency of N-Doping Strategies in the Synthesis of Carbon Dots

“…However, this predominance of C=O groups is higher for samples 1 and 2 (synthesized using small organic small-molecules as precursors) with more than 80% contribution. N 1s spectra can be split into several peaks depending on the samples, with two peaks being present in all CDs at binding energies~400 eV and~401.5 eV, that can be attributed to pyrrolic N (also called C 2 -N-H) and graphitic N (also called N-C 3 ) respectively [51,54,63]. The two first samples present dominant contributions from pyrrolic N group (~89%) and small contribution from graphitic N group (~11%).…”

Annealing effect on UV-illuminated recovery in gas response of graphene-based NO2 sensors

“…The result of Raman spectra could be used to identify the characteristics of graphene including quality, number of layers, strain and doping. [27][28][29] To measure the Hall-effect mobility and hole concentration, four silver balls were fabricated on the graphene surface with the same distance. 30 A Hall measurement system (Bio-Rad HL5500, Nanometrics, U.S.) with a magnetic eld of 0.5 T was used to obtain the carrier mobility and concentrations.…”