#electroluminescence

Toward power-generating displays: A single device that harvests and emits light

A newly developed organic semiconductor device can both generate electricity from light and emit bright visible light, as reported by researchers from Science Tokyo. By carefully designing a material where energy losses are suppressed, the team achieved efficient power conversion and electroluminescence simultaneously, demonstrating a multifunctional platform with potential applications in displays, sensors, and energy-harvesting technologies. Reimagining what a diode can do At the foundation of modern electronics lies the semiconductor diode, serving as one of the main building blocks of integrated circuits, displays, camera sensors, and solar panels.

Over a decade in the making: Lanthanide nanocrystals illuminate new possibilities

In a discovery shaped by more than a decade of steady, incremental effort rather than a dramatic breakthrough, scientists from the National University of Singapore (NUS) and their collaborators demonstrated that great ideas flourish when paired with patience. Flashback to 2011: a small group of young researchers gathered around an aging optical bench at the NUS Department of Chemistry, watching a faint, flickering glow on a screen. Their goal seemed deceptively simple: make an insulating crystal emit light when electricity flowed through it. The challenge, however, was nearly impossible. Lanthanide nanocrystals, known for their chemical stability and pinpoint color purity, were insulators, notoriously resistant to electrical excitation.

Inside the light: How invisible electric fields drive device luminescence

Fleeting electron-hole pairs are giving scientists a new window into optimizing light-emitting devices (LEDs). Using quantum magnetic resonance, Osaka Metropolitan University researchers have discovered how shifting internal electric fields dictate whether these devices shine brightly or dimly. Their study is published in the journal Advanced Optical Materials. Light-emitting electrochemical cells (LECs) are simple, flexible, and low-cost thin-film devices that generate light from an electric current. Unlike conventional organic LEDs, LECs contain just a single active layer—an organic semiconductor blended with mobile ions—sandwiched between two electrodes. This structural simplicity makes them promising tools for next-generation light-emitting technologies. Inside that apparently simple structure, however, things aren't so simple after all.

Theorists propose new approach to electroluminescent cooling that works like inverted solar photovoltaic cells

In a study appearing in PRX Energy, researchers propose a way to improve the performance of electroluminescent cooling by using multilayer semiconductors. The approach, called a multijunction configuration, is already used in some special photovoltaic solar cells. Electroluminescence is the phenomenon behind how LEDs work. It involves adding charge carriers, either electrons or holes, to a semiconductor. This changes the semiconductor's properties, including how it conducts or insulates against the movement of electrical charges. In an LED, the charge carriers cause the semiconductor to emit photons of light. This emission can require more energy than is present in the semiconductor. If this is the case, the excess energy to make light comes from heat around the semiconductor. The result—a semiconductor can cool down by emitting light.

Strategy uses boron-nitrogen covalent bonds to enable high-performance narrowband electroluminescence

To meet the demands of next-generation ultrahigh-definition displays, the organic light-emitting diodes (OLED) industry is actively pursuing the development of narrowband organic light-emitting materials. Within this effort, multiple resonance thermally activated delayed fluorescence (MR-TADF) materials based on boron-nitrogen fused polycyclic aromatic hydrocarbons have gained prominence for their energy efficiency and color purity, capturing the interest of both academia and industry. However, these materials often display long excited-state lifetimes, which can cause severe quenching of triplet excitons and thus reduce device efficiency. Addressing this issue while maintaining narrowband emission remains a crucial challenge. To tackle this, a research team led by Professor Chuluo Yang and Associate Professor Xiaosong Cao at Shenzhen University has introduced a π-conjugation extension strategy using boron-nitrogen covalent bonds, focusing on innovative molecular structures. The team's paper is published in the journal National Science Review.

In research that could lead to a new age in illumination, researchers from Japan and Germany have developed an eco-friendly light-emitting electrochemical cells using new molecules called dendrimers combined with biomass derived electrolytes and graphene-based electrodes. Their findings were published in the journal Advanced Functional Materials. Electroluminescence is the phenomenon where a material emits light in response to a passing electric current. Everything from the screen you're using to read this sentence to the lasers used in cutting edge scientific research are results of the electroluminescence of different materials. Due to its ubiquity and necessity in the modern age, it is only natural that extensive resources go into research and development to make this technology better. "One such example of an emerging technology is 'light-emitting electrochemical cells' or LECs," explains Associate Professor Ken Albrechtfrom Kyushu University's Institute for Materials Chemistry and Engineering and one of the leads of the study. "They have been attracting attention because of their cost advantage over organic light emitting diodes, or OLEDs. Another reason for LECs popularity is their simplified structure."

Light-emitting textiles for diverse flexible and wearable displays

Textile research has highlighted the advances in electroluminescent threads as suitable biomaterials for driving growth in the wearable electronics market. While the direct embroidery of textiles with custom designs and patterns can offer substantial benefits, machine embroidery can challenge the integrity of these threads. In a new report of applied science and engineering published in Science Advances, Seungse Cho and a team of scientists in biomedical engineering and medicine in the U.S., present embroiderable, multicolor, electroluminescent threads in blue, green, and yellow, that show compatibility with standard embroidery methods. The researchers used the threads to stitch decorative designs onto a variety of consumer fabrics, without compromising their wearability or light-emitting capacity. The scientists illuminated specific messages or designs on the consumer products for the purpose of developing emergency alerts on helmet liners and as physical hazard signs.

Weaving atomically thin seams of light with in-plane heterostructures

Researchers from Tokyo Metropolitan University have developed a way to produce high quality monolayers of a selection of different transition metal dichalcogenides which meet over an atomically thin seam. By coating this layer with an ion gel, a mixture of an ionic liquid and a polymer, they could excite light emission along the seam. The light was also found to be naturally circularly polarized, a product of the customizable strain across the boundary. Their results are published in Advanced Functional Materials

Light-emitting diodes (LEDs) have become ubiquitous through their revolutionary impact on nearly all forms of lighting. But as our needs diversify and performance demands grow, there is still a clear need for even more power efficient solutions. One such option involves the application of in-plane heterostructures, where ultra-thin layers of different materials are patterned onto surfaces to produce boundaries. In the case of LEDs, this is where electrons and "holes" (mobile voids in semiconducting materials) recombine to produce light. The efficiency, functionality, and scope of applications for such structures are determined not only by the materials used but by the dimensions and nature of the boundaries, which has led to a great deal of research into controlling their structure at the nanoscale.