Construction and Multifunctional Photonic Applications of Light Absorption-Enhanced Silicon-Based Schottky Coupled Structures.

To expand the detection capabilities of silicon (Si)-based photodetector and address key scientific challenges such as low light absorption efficiency and short carrier lifetime in Si-based graphene photodetector. This work introduces a novel Si-based Schottky coupled structure by in situ growth of 3D-graphene and molybdenum disulfide quantum dots (MoS QDs) on Si substrates using chemical vapor deposition (CVD) and plasma-enhanced chemical vapor deposition (PECVD) techniques. The findings validate the "dual-enhanced absorption" effect, enhancing the understanding of the mechanisms that improve optoelectronic performance.

Achieving Ultra-High Heat Flux Transfer in Graphene Films via Tunable Gas Escape Channels.

Graphene films have been applied in the thermal management of electronic devices due to their high thermal conductivity. However, the ever-increasing power and local heat flux density of electronic chips require graphene films with excellent heat flux carrying capacity. Enhancing the heat flux carrying capacity is highly challenging, and the key is to maintain high thermal conductivity while increasing film thickness.

Coexistence of the Band Filling Effect and Trap-State Filling in the Size-Dependent Photoluminescence Blue Shift of MAPbBr Nanoparticles.

The size-dependent photoluminescence (PL) blue shift in organometal halide perovskite nanoparticles has traditionally been attributed to quantum confinement effects (QCEs), irrespective of nanoparticle size. However, this interpretation lacks rigor for nanoparticles with diameters exceeding the exciton Bohr radius (rB). To address this, we investigated the PL of MAPbBr nanoparticles (MNPs) with diameters ranging from ~2 to 20 nm.

Accelerated proton dissociation in an excited state induces superacidic microenvironments around graphene quantum dots.

Investigating proton transport at the interface in an excited state facilitates the mechanistic investigation and utilization of nanomaterials. However, there is a lack of suitable tools for in-situ and interfacial analysis. Here we addresses this gap by in-situ observing the proton transport of graphene quantum dots (GQDs) in an excited state through reduction of magnetic resonance relaxation time.

Nitrogen-Doped 3D-Graphene Advances Near-Infrared Photodetector for Logic Circuits and Image Sensors Overcoming 2D Limitations.

The limitations of two-dimensional (2D) graphene in broadband photodetector are overcome by integrating nitrogen (N) doping into three-dimensional (3D) structures within silicon (Si) via plasma-assisted chemical vapor deposition (PACVD) technology. This contributes to the construction of vertical Schottky heterojunction broad-spectrum photodetectors and applications in logic devices and image sensors. The natural nanoscale resonant cavity structure of 3D-graphene enhances photon capture efficiency, thereby increasing photocarrier generation.

A Tape-Wrapping Strategy towards Electrochemical Fabrication of Water-Dispersible Graphene.

Graphene has achieved mass production via various preparative routes and demonstrated its uniqueness in many application fields for its intrinsically high electron mobility and thermal conductivity. However, graphene faces limitations in assembling macroscopic structures because of its hydrophobic property. Therefore, balancing high crystal quality and good aqueous dispersibility is of great importance in practical applications.

Symmetry-Triggered Tunable Phosphorescence Lifetime of Graphene Quantum Dots in a Solid State.

Studying the phosphorescent mechanisms of carbon nanostructures synthesized by the "bottom-up" approach is key to understanding the structure modulation and the interfacial properties of carbon nanostructures. In this work, the relationships among symmetry of precursors in the "bottom-up" synthesis, structures of products, and phosphorescence lifetimes of graphene quantum dots (GQDs) are studied. The symmetry matching of precursors in the formation of a D graphene-like framework is considered the key factor in controlling the separability of sp domains in GQDs.

The Synergistic Effect on the Mimetic Optical Structure of Feline Eyes toward Household Health Monitoring of Acute and Chronic Diseases.

A breakthrough in the performance of bionic optical structures will only be achieved if we can obtain an in-depth understanding of the synergy mechanisms operating in natural optical structures and find ways to imitate them. In this work, inspired by feline eyes, an optical substrate that takes advantage of a synergistic effect that occurs between resonant and reflective structures was designed. The synergistic effect between the reflective and resonant components leads to a Raman enhancement factor (EF) of 1.

Fast proton transport enables the magnetic relaxation response of graphene quantum dots for monitoring the oxidative environment .

A magnetic relaxation switch (MRS) that targets small molecules such as HO is difficult to realize because of the small size of the targets, which cannot gather enough MRS probes to form aggregates and generate a difference in magnetic relaxation times. Therefore, the development of small molecule-targeted MRS is strongly dependent on changes in the interfacial structure of the probe, which modulates the proton transport behavior near the probe. Herein, functionalized graphene quantum dots (GQDs) consisting of GQDs with disulfide bonds, polyethylene glycol (PEG), and paramagnetic Gd were used as the MRS probe to sense HO.

Tumor diagnosis using carbon-based quantum dots: Detection based on the hallmarks of cancer.

Carbon-based quantum dots (CQDs) have been shown to have promising application value in tumor diagnosis. Their use, however, is severely hindered by the complicated nature of the nanostructures in the CQDs. Furthermore, it seems impossible to formulate the mechanisms involved using the inadequate theoretical frameworks that are currently available for CQDs.

Fabrication of Carbon-Based Quantum Dots via a "Bottom-Up" Approach: Topology, Chirality, and Free Radical Processes in "Building Blocks".

The discovery of carbon-based quantum dots (CQDs) has allowed opportunities for fluorescence bioimaging, tumor diagnosis and treatment, and photo-/electro-catalysis. Nevertheless, in the existing reviews related to the "bottom-up" approaches, attention is mainly paid to the applications of CQDs but not the formation mechanism of CQDs, which mainly derived from the high complexities during the synthesis of CQDs. Among the various synthetic methods, using small molecules as "building blocks", the development of a "bottom-up" approach has promoted the structural design, modulation of the photoluminescence properties, and control of the interfacial properties of CQDs.

Synergistic Effect of Oxygen- and Nitrogen-Containing Groups in Graphene Quantum Dots: Red Emitted Dual-Mode Magnetic Resonance Imaging Contrast Agents with High Relaxivity.

Contrast agents (CAs) in magnetic resonance imaging generally involve the dissociative Gd. Because of the limited ligancy of Gd, the balance between Gd coordination stability (reducing the concentration of dissociative Gd) and increases in the number of coordination water molecules (enhancing the relaxivity) becomes crucial. Herein, the key factor of the synergistic effect between the O- and N-containing groups of graphene quantum dots for the structural design of CAs with both high relaxivity and low toxicity was obtained.

Investigation of a Highly Sensitive Surface-Enhanced Raman Scattering Substrate Formed by a Three-Dimensional/Two-Dimensional Graphene/Germanium Heterostructure.

Three-dimensional graphene (3D-graphene) is used in surface-enhanced Raman spectroscopy (SERS) because of its plasmonic nanoresonator structure and good ability to interact with light. However, a thin (3-5 nm) layer of amorphous carbon (AC) inevitably appears as a template layer between the 3D-graphene and object substrate when the 3D-graphene layer is synthesized, weakening the enhancement factor. Herein, two-dimensional graphene (2D-graphene) is employed as a template layer to directly synthesize 3D-graphene on a germanium (Ge) substrate via plasma-assisted chemical vapor deposition, bypassing the formation of an AC layer.

Sensitive, Reusable, Surface-Enhanced Raman Scattering Sensors Constructed with a 3D Graphene/Si Hybrid.

Surface-enhanced Raman scattering (SERS) substrates based on graphene and its derivatives have recently attracted attention among those interested in the detection of trace molecules; however, these substrates generally show poor uniformity, an unsatisfactory enhancement factor, and require a complex fabrication process. Herein, we design and fabricate three-dimensional (3D) graphene/silicon (3D-Gr/Si) heterojunction SERS substrates to detect various types of molecules. Notably, the detection limit of 3D-Gr/Si can reach 10 M for rhodamine 6G (R6G) and rhodamine B (RB), 10 M for crystal violet (CRV), copper(II) phthalocyanine (CuPc), and methylene blue (MB), 10 M for dopamine (DA), 10 M for bovine serum albumin (BSA), and 10 M for melamine (Mel), which is superior to most reported graphene-based SERS substrates.

Magnetic graphene quantum dots facilitate closed-tube one-step detection of SARS-CoV-2 with ultra-low field NMR relaxometry.

The rapid and sensitive diagnosis of the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the crucial issues at the outbreak of the ongoing global pandemic that has no valid cure. Here, we propose a SARS-CoV-2 antibody conjugated magnetic graphene quantum dots (GQDs)-based magnetic relaxation switch (MRSw) that specifically recognizes the SARS-CoV-2. The probe of MRSw can be directly mixed with the test sample in a fully sealed vial without sample pretreatment, which largely reduces the testers' risk of infection during the operation.

Graphene Quantum Dots with Pyrrole N and Pyridine N: Superior Reactive Oxygen Species Generation Efficiency for Metal-Free Sonodynamic Tumor Therapy.

Those responsible for the development of sonosensitizers are faced with a dilemma between high sonosensitization efficacy and good biosecurity that limited the development of sonodynamic therapy (SDT). Herein, inspired by the intriguing therapeutic features of SDT and the potential catalytic activity of graphene quantum dots, the potential of N-doped graphene quantum dots (N-GQDs) to act as a sonosensitizer is demonstrated. The superior sonosensitization effect of N-GQDs is believed to be three to five times higher than that of traditional sonosensitizers (such as porphyrin, porphyrin Mn, porphyrin Zn, TiO , etc.

Coordinating capillary infiltration with anodic oxidation: a multi-functional strategy for electrochemical fabrication of graphene.

Electrochemical exfoliation of graphite stands out as a promising alternative to the existing methods for scalable graphene fabrication. However, factors governing the electrochemical process and the underlying mechanism are complex and how to effectively control the exfoliation process is far from completely clear despite many attempts in previous works. Herein, for the first time, capillary infiltration, anodic oxidation and their dependence on temperature were found to be critical in determining the electrolyte infiltration and the anodic oxidation process.

Imaging Cellular Aerobic Glycolysis using Carbon Dots for Early Warning of Tumorigenesis.

Early warning of tumor formation is crucial for the classification, treatment, and prognosis of tumor patients. Here, a new strategy is reported, aimed at realizing this goal based on imaging aerobic glycolysis processes using nitrogen-doped carbon dots (N-CDs) as fluorescent probes. The intensity of the photoluminescence emitted by the N-CDs is specifically enhanced by nicotinamide adenine dinucleotide (NAD , oxidized) in the physiological environment.

Carbon-Based Quantum Dots with Solid-State Photoluminescent: Mechanism, Implementation, and Application.

Carbon-based quantum dots (CQDs), including spherical carbon dots and graphene quantum dots, are an emerging class of photoluminescent (PL) materials with unique properties. Great progress has been made in the design and fabrication of high-performance CQDs, however, the challenge of developing solid-state PL CQDs have aroused great interest among researchers. A clear PL mechanism is the basis for the development of high-performance solid-state CQDs for light emission and is also a prerequisite for the realization of multiple practical applications.

Ultra-low noise graphene/copper/nylon fabric for electromagnetic interference shielding in ultra-low field magnetic resonance imaging.

In ultra-low-field magnetic resonance imaging (ULF MRI) working in the micro-tesla magnetic field range, the superconducting quantum interference device (SQUID) as the signal detector is very susceptible to electromagnetic interference (EMI) so that the system normally works in a shielded room. However, the leakage of EMI in the shielded room may still seriously reduce the system performance. In order to improve the electromagnetic compatibility of the system, we designed a microwave absorbing composite, graphene/Cu/nylon fabric (GCN fabric).

Enhancing the magnetic relaxivity of MRI contrast agents via the localized superacid microenvironment of graphene quantum dots.

The design of contrast agents (CAs) with high magnetic relaxivities is a key issue in the field of magnetic resonance imaging (MRI). The traditional strategy employed is aimed at optimizing the structural design of the magnetic atoms in the CA. However, it is difficult to obtain an agent with magnetic relaxivity over 100 mM s using this approach.

Interface Engineering-Assisted 3D-Graphene/Germanium Heterojunction for High-Performance Photodetectors.

Three-dimensional graphene (3D-Gr) with excellent light absorption properties has received enormous interest, but in conventional processes to prepare 3D-Gr, amorphous carbon layers are inevitably introduced as buffer layers that may degrade the performance of graphene-based devices. Herein, 3D-Gr is prepared on germanium (Ge) using two-dimensional graphene (2D-Gr) as the buffer layer. 2D-Gr as the buffer layer facilitates the in situ synthesis of 3D-Gr on Ge by plasma-enhanced chemical vapor deposition (PECVD) by promoting 2D-Gr nucleation and reducing the barrier height.

Polarizing Graphene Quantum Dots toward Long-Acting Intracellular Reactive Oxygen Species Evaluation and Tumor Detection.

The evaluation of intracellular reactive oxygen species (ROS) would greatly deepen the understanding of cell metabolism/proliferation and tumor detection. However, current long-acting level tracking techniques for intracellular ROS remain unsuited to practical applications. To solve this problem, we synthesized cyclotriphosphazene-doped graphene quantum dots (C-GQDs) whose quantum yield is highly sensitive to ROS (increased by 400% from 0.

"Self-Matched" Tribo/Piezoelectric Nanogenerators Using Vapor-Induced Phase-Separated Poly(vinylidene fluoride) and Recombinant Spider Silk.

Flexible biocompatible mechanical energy harvesters are drawing increasing interest because of their high energy-harvesting efficiency for powering wearable/implantable devices. Here, a type of "self-matched" tribo-piezoelectric nanogenerators composed of genetically engineered recombinant spider silk protein and piezoelectric poly(vinylidene fluoride) (PVDF)-decorated poly(ethylene terephthalate) (PET) layers is reported. The PET layer serves as a shared structure and electrification layer for both piezoelectric and triboelectric nanogenerators.

Photocatalytic Polymerization from Amino Acid to Protein by Carbon Dots at Room Temperature.

The chemical origins of life have been widely accepted at the present stage. However, the idea that amino acids further react to produce peptides and proteins remains an unsatisfactory explanation, because producing polypeptides via spontaneous reaction of amino acids in solution is extremely difficult. It is also necessary to further answer whether amino acids can form longer peptide chains as well as specific chiral structures and so on under this same reaction mechanism.