Technical / Research

Researchers from Malaysia have advanced the development of next-generation bifacial dye-sensitized solar cells (DSSCs) by integrating graphene into a trilayer photoanode configuration to boost both efficiency and stability. The team focused on a titanium dioxide (TiO₂)–based [T/sp-P25-T/sp] stack formation framework, where varying concentrations of graphene (0.05%, 0.1%, and 0.2%) were introduced to optimize electron transport and suppress recombination losses.

Among the tested samples, the photoanode doped with 0.1% graphene achieved the best performance, delivering a combined power conversion efficiency (PCE) of 11.09% under dual illumination and maintaining 10.31% after ten days of operation. This represents an improvement over undoped TiO₂ structures. Key analytical techniques - including FESEM, EDS, Raman spectroscopy, XRD, UV–Vis spectroscopy, and electrochemical impedance spectroscopy (EIS) - confirmed that graphene was successfully embedded within the anatase TiO₂ matrix without structural compromise.

Researchers at the Institute of Science Tokyo, Japan Science and Technology Agency (JST) and Nagoya University have created a new way to study the mechanical behavior of graphene nanosheets. The technique enables direct measurement of bending rigidity in sheets with structural defects, without the need for laboratory experiments. 

Graphene's structure sometimes includes rings of five or seven carbon atoms instead of the usual six. These "defects" change the sheet's shape - five-membered rings make it cone-like, while seven-membered rings give it a saddle shape. Until now, it was hard to measure how these defects affect the sheet's ability to bend without using complicated experiments. The new approach combines powerful computer simulations and a theory used for describing the bending of biological membranes. This makes it possible to predict how sheets with different types or arrangements of defects will bend, just by looking at their atomic structure.

Atomically thin 2D materials are promising candidates for extending Moore’s Law due to their exceptional geometric and electronic properties. However, the realization of ultrathin p–n junctions, as crucial components of modern electronic and optoelectronic devices, remains a significant challenge due to the limitations of traditional doping techniques used in bulk materials.

Researchers at Nanjing University of Posts and Telecommunications, Chizhou University, Henan University of Science and Technology and Yangzhou University have found that interlayer twisting can facilitate the formation of self-doped p–n junctions in 2D materials based on first-principles calculations combined with nonadiabatic molecular dynamics and nonequilibrium Green’s function methods. 

The generation of electricity from heat, also known as thermoelectric energy conversion, is advantageous for various real-world applications. For instance, it proved useful for the generation of energy during space expeditions and military missions in difficult environments, as well as for the recovery of waste heat produced from industrial plants, power stations or even vehicles.

The successful conversion of heat into electricity relies on one of two distinct effects, known as the Seebeck effect and the Nernst effect. The Seebeck effect occurs when two dissimilar materials are joined at two junctions that are at different temperatures, which can generate an electric current flowing in the loop. The Nernst effect, on the other hand, entails the generation of a transverse voltage in a material with a temperature gradient.

Researchers at Harvard University and their collaborators have used a specially designed microscope to probe the properties of supermoiré patterns in trilayer graphene to an extent that was never possible before. 

Using the unique microscope, they detected many new states of matter in which electrons would get stuck or form unusual groups, leading to changes in the entire system’s electronic behavior and opening doors to studying layered materials with precisely controllable properties.  

Researchers at Soochow University, University of Science and Technology of China, Peking University, ShanghaiTech University, Beijing Graphene Institute and additional collaborators have developed a copper-based growth process that produces large-area trilayer graphene films with uniform thickness and improved mechanical strength.

Schematic representation illustrating the synchronous growth process catalyzed by the heterogeneous Cu–Cu2O substrate. Inset: schematic of the graphene edge–Cu–Cu2O three-phase interfaces. Image from: Nature Communications

The team stated that much of graphene's functional promise - especially in electronics and optoelectronics - relies not on the single-layer form that dominates laboratory work, but on precise multilayer structures. Adding layers enables electronic band structures to be tuned and improves properties such as stiffness and thermal transport. Despite this, the controlled synthesis of multilayer graphene films with consistent thickness across large areas has remained quite elusive.

In systems with multiple energy bands, the interplay between electrons with different effective masses drives correlated phenomena that do not occur in single-band systems. Magic-angle twisted trilayer graphene is a tunable platform for exploring such effects, hosting both heavy ("bound") electrons and light ("weakly bound and mobile") electrons. 

Researchers at Harvard, MIT and National Institute for Material Science in Japan have examined the interplay between "light" and "heavy" electrons in magic-angle twisted trilayer graphene, shedding new light on how they may help form novel quantum states.

Vacuum is perceived as empty, but in fact it is full of fleeting energy fluctuations - virtual photons popping in and out of existence that can interact with matter, giving rise to new, potentially useful properties. Researchers use optical cavities, structures made of mirrors facing one another, to confine these fluctuations, harnessing their effects to engineer new forms of matter. Conventional optical cavities boost fluctuations, or vacuum fields, for both right- and left-handed circularly polarized light. 

Researchers at Rice University, Harvard University and Max Planck Institute have developed a new cavity design that selectively enhances the quantum vacuum fluctuations of circularly polarized light in a single direction, achieving chirality - a feat that typically requires the use of a strong magnetic field. The team used lightly doped indium antimonide to construct the chiral cavity. The researchers also conducted comprehensive theoretical investigations to predict how the new cavity design would transform the properties of materials placed inside it.

Researchers at Korea's Electronics and Telecommunications Research Institute (ETRI) have succeeded in developing an innovative transparent film using graphene. The film’s transparency changes depending on the intensity of light, and is expected to be used in a variety of fields, including laser protection devices, smart optical sensors, and artificial intelligence (AI) photonic materials.

Graphene has been challenging to utilize in real-world applications due to issues with adhesion. Although chemical dispersants have been employed to address this problem, they often compromise graphene’s intrinsic properties. The ETRI team's new photocurable graphene-dispersed colloid could address this issue and enable graphene to be stably and uniformly dispersed within a polymer without a dispersant. 

Atomically thin suspended graphene can be used as NEMS transducers for ultra-small and high-performance sensors thanks to its excellent mechanical and electrical properties. Most applications of suspended graphene in NEMS devices are limited to pressure sensors, resonators, switches, etc. Graphene-based NEMS accelerometers have rarely been reported, with limitations such as mechanical robustness, life span and device yield, thereby limiting their practical applications.

Researchers from the Beijing Institute of Technology and North University of China have developed piezoresistive graphene-based NEMS accelerometers with high manufacturing yield, excellent mechanical robustness and stability, and long life span, in which the width of trenches for suspending graphene membranes was only 1 µm and fully-clamped suspended double-layer graphene membranes with an attached SiO₂/Si proof mass was used as acceleration transducer.