Controlled Preparation and Device Application of Sub-5 nm Graphene Nanoribbons and Graphene Nanoribbon/Carbon Nanotube Intramolecular Heterostructures

Abstract

Narrow graphene nanoribbons (GNRs) and GNR/single-walled carbon nanotube (SWNT) intramolecular heterojunctions are ideal candidates to construct next-generation electronic and optoelectronic devices. However, the fabrication of high-quality long sub-5 nm wide GNRs and GNR/SWNT heterojunctions is a great challenge. Here, we report a method to produce high-quality sub-5 nm wide GNRs with smooth edges and GNR/SWNT intramolecular heterostructures via palladium-catalyzed full and partial unzipping of SWNTs, respectively. The resulting GNRs could be as narrow as 2.2 nm and had an average length of over 1 μm. By adjusting the unzipping time and the deposited positions of palladium nanoparticles, controlled multiple GNR/SWNT heterostructures were also fabricated on an individual parent SWNT. A GNR field-effect transistor (FET) constructed by a 3.1 nm wide GNR could simultaneously achieve a high on/off current ratio of 1.1 × 104 and a large mobility of 598 cm2 V–1 s–1. The photovoltaic device based on a single GNR (2.4 nm in width)/SWNT (0.8 nm in diameter) heterojunction exhibited a large open-circuit voltage (V oc) of 0.52 V and a high external power conversion efficiency (η) of 4.7% under the 1550 nm wavelength illumination of 931 mW cm–2. Our method provides a pathway to controllably prepare high-quality sub-5 nm GNRs and GNR/SWNT heterojunctions for fundamental studies and practical applications in the electronic and optoelectronic fields.

High-Performance Infrared Detectors Based on Black Phosphorus/Carbon Nanotube Heterojunctions

“…Within the sensitive area (BP/SWCNT stacking area; Figure 4b blue box), P in was calculated to be 672 nW. The external η of the device was calculated to be 7.5%, which was the highest among the photovoltaic devices fabricated with the SWCNTs or the heterostructures based on the 2D materials [13,21,[30][31][32][33]. The detail comparison is shown in Table 1.…”

“…A BP/graphene heterostructure had also been used to construct a photovoltaic detector [20]. However, the device sensitivity is relatively low because the monolayer graphene used had a weak photoabsorption [21]. In contrast, a dense SWCNT film has a stronger photo absorption than a monolayer graphene while maintaining a similar carrier mobility as the graphene.…”

Design of silicon-on-insulator field-effect transistor using graphene channel to improve short channel effects over conventional devices

“…The interlayer spacing affects the bandgap. By fabricating GFET, He et al [35] solved the problem of edge roughness. The creation of a new graphene and carbon nanotube heterostructure for 5 nm technology is described.…”

Electronic and Electrical Properties of Island-Type Hybrid Structures Based on Bi-Layer Graphene and Chiral Nanotubes: Predictive Analysis by Quantum Simulation Methods

“…The fabricated barrister showed an electron mobility of ~5350 cm 2 /Vs and current on/off ratio of 10 6 . Using palladium-catalyzed partial unzipping of SWCNTs, intramolecular heterojunctions based on graphene nanoribbons (2.4 nm in width) and SWCNTs (0.8 nm in diameter) were obtained [46]. The photovoltaic device based on these heterojunctions demonstrated a large open-circuit voltage of 0.52 V and a high efficiency of external power conversion of 4.7% under illumination with a wavelength of 1550 nm.…”