Nonlocal Response in Infrared Detector with Semiconducting Carbon Nanotubes and Graphdiyne

Promoting CO2 electroreduction to CO by a graphdiyne-stabilized Au nanoparticle catalyst

The electrochemical CO2 reduction reaction (CO2RR) gives an ideal approach for producing valuable chemicals, offering dual benefits in terms of environmental preservation and carbon recycling. In this work, a strong synergistic effect is constructed by adopting electron-rich graphdiyne (GDY) as the supporting matrix, which significantly stabilizes the Au active sites and boosts the CO2RR process. The as-prepared GDY-supported Au nanoparticles (Au/GDY) exhibit excellent CO2RR performance, with an extremely high faradaic efficiency of 94.6% for CO as well as good stability with continuous electrolysis for 36 hours. The superior activity and stability of the Au/GDY catalyst can be attributed to the electronic interaction between Au nanoparticles and the GDY substrate, resulting in enhanced electron transfer rates and a stable network of catalytically active sites that ultimately promote the CO2RR.

Graphdiyne and Its Derivatives as Efficient Charge Reservoirs and Transporters in Semiconductor Devices

2D graphdiyne (GDY), which is composed of sp and sp² hybridized carbon atoms, is a promising semiconductor material with a unique porous lamellar structure. It has high carrier mobility, tunable bandgap, high density of states, and strong electrostatic interaction ability with ions and organic functional units. In recent years, interests in applying GDYs (GDY and its derivatives) in semiconductor devices have been growing rapidly, and great achievements have been made. Attractively, GDYs could act as efficient reservoirs and transporters for both carriers and ions, which endows them with enormous potential in future novel optoelectronics. In this review, the progress in this field is systematically summarized, aiming to bring an in-depth insight into the GDYs' intrinsic uniqueness. Particularly, the effects of GDYs on carrier dynamics and ionic interactions in various semiconductor devices are succinctly described, analyzed, and concluded.

Graphdiyne applications in sensors: A bibliometric analysis and literature review

Graphdiyne is a two-dimensional carbon nanomaterial synthesized artificially in 2010. Its outstanding performance is considered to have great potential in different fields. This article summarizes the work of graphdiyne in the sensing field by literature summary and bibliometrics analysis. The development of graphdiyne in the field of sensing has gone through a process from theoretical calculation to experimental verification. Especially in the last three years, there has been very rapid development. The theoretical calculations suggest that graphdiyne is an excellent gas sensing material, but there is little experimental evidence in this direction. On the contrary, graphdiyne has been widely reported in the field of electrochemical sensing. At the same time, graphdiyne can also be used as a molecular switch for DNA sequencing. Fluorescent sensors based on graphdiyne have also been reported. In general, the potential of graphdiyne in sensing still needs to be explored. Current research results do not show that graphdiyne has irreplaceable advantages in sensing. The bibliometric analysis used in this review also provides cooperative network analysis and co-citation analysis on this topic. This provides a reference for the audience wishing to undertake research on the topic. In addition, according to the analysis, we also listed the direction that which this field deserves attention in the future.

Single-Walled Carbon Nanotube-Germanium Heterojunction for High-Performance Near-Infrared Photodetector

In this research, we report on a high-performance near-infrared (near-IR) photodetector based on single-walled carbon nanotube-germanium (SWCNT-Ge) heterojunction by assembling SWCNT films onto n-type Ge substrate with ozone treatment. The ozone doping enhances the conductivity of carbon nanotube films and the formed interfacial oxide layer (GeOx) suppresses the leakage current and carriers’ recombination. The responsivity and detectivity in the near-IR region are estimated to be 362 mA W−1 and 7.22 × 1011 cm Hz1/2 W−1, respectively, which are three times the value of the untreated device. Moreover, a rapid response time of ~11 μs is obtained simultaneously. These results suggest that the simple SWCNT-Ge structure and ozone treatment method might be utilized to fabricate high-performance and low-cost near-IR photodetectors.

2D graphdiyne: an emerging carbon material

As a new member of carbon allotropes, graphdiyne (GDY) has the characteristics of being one-atom-thick with two-dimensional layers comprising sp and sp² hybridized carbon atoms, and represents a trend in the development of carbon materials. Its unique chemical and electronic structures give GDY many unique and fascinating properties such as rich chemical bonds, highly conjugated and super-large π structures, infinitely distributed pores and high inhomogeneity of charge distribution. GDY has entered a period of rapid development, especially with the significant emergence of fundamental research and applied research achievements over the past five years. As one of the frontiers of chemistry and materials science, graphdiyne was listed in the Top 10 research areas in the 2020 Research Frontiers report and was jointly released in the Top 10 in the world by Clarivate and the Chinese Academy of Sciences. The research results have shown the great potential of GDY in the applications of energy, catalysis, environmental science, electronic devices, detectors, biomedicine and therapy, etc. Scientists are eager to explore and fully reveal the new properties, discover new scientific concepts and phenomena, discover the new conversion modes and mechanisms of GDY in photoelectricity, energy, and catalysis, etc., and build the important scientific value of new conversion devices. This review covers research on the foundation and application of GDY, such as the controlled preparation of new methods of GDY and GDY-based materials, studies on new mechanisms and properties in chemistry and physics, and the foundation and applications in energy, catalysis, photoelectric and devices.

Graphdiyne-deposited microfiber structure all-optical modulator at the telecommunication band

All-optical modulator is a crucial device in next generation of all-optical communications, interconnects, and signal processing. Here, we demonstrate an all-optical phase modulator with graphdiyne (GDY)-deposited microfiber structure. The phase shift of the signal light can be readily controlled by pump light by thermo-optic effect. This all-optical modulator can achieve a phase shift slope of 0.0296 π·mW^-1 and a rising time of 5.48 ms at 25 Hz (3 ms, 50 Hz). Modes distributions in GDY-deposited microfiber at different wavelength are numerical analyzed and the normalized phase conversion efficiency of GDY are calculated. The results show that GDY has a considerable normalized phase conversion efficiency of 0.1644 π·mW^-1·mm^-1, which is higher than that of graphene, MXene and WS₂ based all-optical modulators. This work proves the potential of GDY in all-optical modulator device at telecommunication band and provides a support to all-optical signal processing systems.

Direct Charge Trapping Multilevel Memory with Graphdiyne/MoS2 Van der Waals Heterostructure

Direct charge trapping memory, a new concept memory without any dielectric, has begun to attract attention. However, such memory is still at the incipient stage, of which the charge-trapping capability depends on localized electronic states that originated from the limited surface functional groups. To further advance such memory, a material with rich hybrid states is highly desired. Here, a van der Waals heterostructure design is proposed utilizing the 2D graphdiyne (GDY) which possesses abundant hybrid states with different chemical groups. In order to form the desirable van der Waals coupling, the plasma etching method is used to rapidly achieve the ultrathin 2D GDY with smooth surface for the first time. With the plasma-treated 2D GDY as charge-trapping layer, a direct charge-trapping memory based on GDY/MoS2 is constructed. This bilayer memory is featured with large memory window (90 V) and high degree of modulation (on/off ratio around 8 × 107 ). Two operating mode can be achieved and data storage capability of 9 and 10 current levels can be obtained, respectively, in electronic and opto-electronic mode. This GDY/MoS2 memory introduces a novel application of GDY as rich states charge-trapping center and offers a new strategy of realizing high performance dielectric-free electronics, such as optical memories and artificial synaptic.

Artificial Carbon Graphdiyne: Status and Challenges in Nonlinear Photonic and Optoelectronic Applications

The creative integration of sp-hybridized carbon atoms into artificial carbon graphdiyne has led to graphdiyne with superior properties in terms of uniformly distributed pores, ambipolar carrier transport, natural bandgap, and broadband absorption. Consequently, graphdiyne, regarded as a promising carbon material, has garnered particular attention in light-matter interactions. Light-matter interactions play an important role in optical information technology and meet the increasing demand for various energy sources. Herein, the status and challenges in nonlinear photonic and optoelectronic applications of graphdiyne, which are still in the infancy stage, are summarized. Furthermore, the bottleneck and perspective of graphdiyne in these aspects are discussed. It is therefore anticipated that this review could promote the development of graphdiyne in photonic and optoelectronic fields.

Graphdiyne-Based Flexible Photodetectors with High Responsivity and Detectivity

Graphdiyne (GDY), a newly emerging 2D carbon allotrope, has been widely explored in various fields owing to its outstanding electronic properties such as the intrinsic bandgap and high carrier mobility. Herein, GDY-based photoelectrochemical-type photodetection is realized by spin-coating ultrathin GDY nanosheets onto flexible poly(ethylene terephthalate) (PET) substrates. The GDY-based photodetectors (PDs) demonstrate excellent photo-responsive behaviors with high photocurrent (P_ph , 5.98 µA cm^{- 2} ), photoresponsivity (R_ph , 1086.96 µA W^{- 1} ), detectivity (7.31 × 10¹⁰ Jones), and excellent long-term stability (more than 1 month). More importantly, the PDs maintain an excellent P_ph after 1000 cycles of bending (4.45 µA cm^{- 2} ) and twisting (3.85 µA cm^{- 2} ), thanks to the great flexibility of the GDY structure that is compatible with the flexible PET substrate. Density functional theory (DFT) calculations are adopted to explore the electronic characteristics of GDY, which provides evidence for the performance enhancement of GDY in alkaline electrolyte. In this way, the GDY-based flexible PDs can enrich the fundamental study of GDY and pave the way for the exploration of GDY heterojunction-based photodetection.

Graphdiyne and its Assembly Architectures: Synthesis, Functionalization, and Applications

Graphdiyne (GDY), a novel one-atom-thick carbon allotrope that features assembled layers of sp- and sp² -hybridized carbon atoms, has attracted great interest from both science and industry due to its unique and fascinating structural, physical, and chemical properties. GDY-based materials with different morphologies, such as nanowires, nanotube arrays, nanosheets, and ordered stripe arrays, have been applied in various areas such as catalysis, solar cells, energy storage, and optoelectronic devices. After an introduction to the fundamental properties of GDY, recent advances in the fabrication of GDY-based nanostructures and their applications, and corresponding mechanisms, are covered, and future critical perspectives are also discussed.

The Accelerating World of Graphdiynes

Graphdiyne (GDY), a 2D allotrope of graphene, is first synthesized in 2010 and has attracted attention as a new low-dimensional carbon material. This work surveys the literature on GDYs. The history of GDYs is summarized, including their relationship with 2D graphyne carbons and yearly publication trends. GDY is a molecule-based nanosheet woven from a molecular monomer, hexaethynylbenzene; thus, it is synthesized by bottom-up approaches, which allow rich variation via monomer design. The GDY family and the synthetic procedures are also described. Highly developed π-conjugated electronic structures are common important features in GDY and graphene; however, the coexistence of sp and sp² carbons differentiates GDY from graphene. This difference gives rise to unique physical properties, such as high conductivity and large carrier mobility. Next, the theoretical and experimental studies of these properties are described in detail. A wide variety of applications are proposed for GDYs, including electrocatalysts and energy devices, which exploit the carbon-rich nature, porous framework, and expanded π-electron system of these compounds. Finally, potential uses are discussed.

Kerr Nonlinearity in 2D Graphdiyne for Passive Photonic Diodes

Graphdiyne is a new carbon allotrope comprising sp- and sp² -hybridized carbon atoms arranged in a 2D layered structure. In this contribution, 2D graphdiyne is demonstrated to exhibit a strong light-matter interaction with high stability to achieve a broadband Kerr nonlinear optical response, which is useful for nonreciprocal light propagation in passive photonic diodes. Furthermore, advantage of the unique Kerr nonlinearity of 2D graphdiyne is taken and a nonreciprocal light propagation device is proposed based on the novel similarity comparison method. Graphdiyne has demonstrated a large nonlinear refractive index in the order of ≈10^-5 cm² W^-1 , comparing favorably to that of graphene. Based on the strong Kerr nonlinearity of 2D graphdiyne, a nonlinear photonic diode that breaks time-reversal symmetry is demonstrated to realize the unidirectional excitation of Kerr nonlinearity, which can be regarded as a significant demonstration of a graphdiyne-based prototypical application in nonlinear photonics and might suggest an important step toward versatile graphdiyne-based advanced passive photonics devices in the future.

Graphynes: indispensable nanoporous architectures in carbon flatland

Theoretical design and experimental realization of novel nanoporous architectures in carbon membranes has been a success story in recent times. Research on graphynes, an interesting class of materials in carbon flatland, has contributed immensely to this success story. Graphyne frameworks possessing sp and sp2 hybridized carbon atoms offer a variety of uniformly distributed nanoporous architectures for applications ranging from water desalination, gas separation, and energy storage to catalysis. Theory has played a pivotal role in research on graphynes, starting from the prediction of various structural forms to the emergence of their remarkable applications. Herein, we attempt to provide an up-to-date account of research on graphynes, highlighting contributions from numerous theoretical investigations that have led to the current status of graphynes as indispensable materials in carbon flatland. Despite unsolved challenges in large-scale synthesis, the future appears bright for graphynes in present theoretical and experimental research scenarios.