To realize graphene-based electronics, various types of graphene are required; thus, modulation of its electrical properties is of great importance. Theoretic studies show that intentional doping is a promising route for this goal, and the doped graphene might promise fascinating properties and widespread applications. However, there is no experimental example and electrical testing of the substitutionally doped graphene up to date. Here, we synthesize the N-doped graphene by a chemical vapor deposition (CVD) method. We find that most of them are few-layer graphene, although single-layer graphene can be occasionally detected. As doping accompanies with the recombination of carbon atoms into graphene in the CVD process, N atoms can be substitutionally doped into the graphene lattice, which is hard to realize by other synthetic methods. Electrical measurements show that the N-doped graphene exhibits an n-type behavior, indicating substitutional doping can effectively modulate the electrical properties of graphene. Our finding provides a new experimental instance of graphene and would promote the research and applications of graphene.

Organic field-effect transistors (OFETs) have attracted much attention in the past decades because of their potential applications in large-area, flexible, and low-cost electronics. [1][2][3][4][5][6][7] The device performance is not only governed by the intrinsic electrical characteristics of the organic semiconductors, but also dependent on the work function of the source/ drain (S/D) electrodes and the interface contact between the organic semiconductors and the S/D electrodes. Metal S/D electrodes are widely used to fabricate OFETs, although a large contact resistance exists between the organic semiconductor and the metal S/D electrodes, especially for devices with bottom-contact geometry. The selection of S/D electrodes with high carrier injection efficiency and excellent interface properties with organic semiconductors is a current challenge in the quest for improving the performance of OFETs and decreasing the device cost. Graphene is a basic building block of graphite, fullerene, and carbon nanotubes. According to the layer number, graphenes can be distinguished as three types: single-, double-, and few-(3-10) layer graphene.[8] Two-dimensional graphene was obtained only very recently, and it has been the focus of great interest because it could provide an excellent subject for study in condensed-matter physics and material sciences.[8]The unusual and stable structure of this new material makes it a promising candidate for future electronic applications. To date, only three methods -mechanical exfoliation of graphite on SiO 2 /Si, thermal decomposition of SiC, and oxidation of graphite -have been used to obtain graphene. [9][10][11][12] However, using these ways it is difficult to pattern the graphene layer, which is necessary in order to study the electrical properties. In this Communication, we report a novel approach to preparing and patterning graphene layers on a SiO 2 /Si substrate and demonstrate that they can be used as an electrode material suitable for low-cost electronics. The graphene electrodes exhibited excellent hole-injection characteristics and outstanding interface contact with the organic semiconductor. The pentacene-based OFETs showed a high mobility of 0.53 cm 2 V À1 s À1

Graphene has attracted much interest in both academia and industry. The challenge of making it semiconducting is crucial for applications in electronic devices. A promising approach is to reduce its physical size down to the nanometer scale. Here, we present the surface-assisted bottom-up fabrication of atomically precise armchair graphene nanoribbons (AGNRs) with predefined widths, namely 7-, 14- and 21-AGNRs, on Ag(111) as well as their spatially resolved width-dependent electronic structures. STM/STS measurements reveal their associated electron scattering patterns and the energy gaps over 1 eV. The mechanism to form such AGNRs is addressed based on the observed intermediate products. Our results provide new insights into the local properties of AGNRs, and have implications for the understanding of their electrical properties and potential applications.

Graphene, a two-dimensional material, is regarded as one of the most promising candidates for future nanoelectronics due to its atomic thickness, excellent properties and widespread applications. As the first step to investigate its properties and finally to realize the practical applications, graphene must be synthesized in a controllable manner. Thus, controllable synthesis is of great significance, and received more and more attention recently. This Progress Report highlights recent advances in controllable synthesis of graphene, clarifies the problems, and prospects the future development in this field. The applications of the controllable synthesis are also discussed.