Electronic components embedded in a single graphene nanoribbon

Abstract

The use of graphene in electronic devices requires a band gap, which can be achieved by creating nanostructures such as graphene nanoribbons. A wide variety of atomically precise graphene nanoribbons can be prepared through on-surface synthesis, bringing the concept of graphene nanoribbon electronics closer to reality. For future applications it is beneficial to integrate contacts and more functionality directly into single ribbons by using heterostructures. Here, we use the on-surface synthesis approach to fabricate a metal-semiconductor junction and a tunnel barrier in a single graphene nanoribbon consisting of 5- and 7-atom wide segments. We characterize the atomic scale geometry and electronic structure by combined atomic force microscopy, scanning tunneling microscopy, and conductance measurements complemented by density functional theory and transport calculations. These junctions are relevant for developing contacts in all-graphene nanoribbon devices and creating diodes and transistors, and act as a first step toward complete electronic devices built into a single graphene nanoribbon.

Engineered electronic states in atomically precise artificial lattices and graphene nanoribbons

“…ZGNRs [26]). Eventually, embedding more functionality into the single GNRs through heterostructures [30,31,146] or topological properties [86,87] should allow the realization of more complex GNR devices. In the case of artificial lattices, practical applications are further into the future.…”

“…Mixing nearly metallic GNR segments with wider band gap regions allows the realization of structures resembling a tunneling barrier with metallic leads (Fig. 6c) [146]. Since ultranarrow 5-AGNRs are nearly metallic [32], metal-semiconductor junctions can be achieved four monomer unit long 7-AGNR segment works effectively as a tunnel barrier between nearly metallic 5-AGNR leads (Fig.…”

“…Since ultranarrow 5-AGNRs are nearly metallic [32], metal-semiconductor junctions can be achieved four monomer unit long 7-AGNR segment works effectively as a tunnel barrier between nearly metallic 5-AGNR leads (Fig. 6c) [146]. In addition to LDOS maps, it would be very desirable to be able to probe transport through these atomically well-defined GNR heterostructures.…”

Design of Atomically Precise Nanoscale Negative Differential Resistance Devices

“…The new device designed with multiple segments exhibits qualitatively better NDR characteristics and reasonable absolute current. [17,41,43] However, due to heightdependent variations of the sample-substrate coupling, [44] the band alignment in the HS can change in the lift-up configuration. It is found that the NDR feature of the 5-part structure is highly tolerant of variations in the segment widths.…”

“…[2][3][4][5][6][7][8][9][10][11][12][13] The recent development of graphene and graphene nanoribbons (GNRs) offers new opportunities to design nanoscale devices and to test NDR at the atomic scale. [15][16][17][18][19][20][21][22][23] In particular, controllable polymer-to-GNR conversion reaction was demonstrated using charge injection from a scanning tunneling microscope (STM) tip. [15][16][17][18][19][20][21][22][23] In particular, controllable polymer-to-GNR conversion reaction was demonstrated using charge injection from a scanning tunneling microscope (STM) tip.…”