The Chemical Connection: Onshoring PCB Production—Daunting but Certainly Possible
It’s Only Common Sense: The Phone Is Still Mightier Than the Keyboard
Record Efficiency for Perovskite-based LEDs
March 28, 2019 | Linköping UniversityEstimated reading time: 2 minutes
Efficient near-infrared (NIR) light-emitting diodes of perovskite have been produced in a laboratory at Linköping University. The external quantum efficiency is 21.6%, which is a record.
The work is led by LiU scientist Feng Gao, in close collaboration with colleagues in China, Italy, Singapore and Switzerland.
Perovskites are a group of materials defined by their crystal structure, and have been the focus of intense research interest during the past 10 years, initially for solar cells and recently also for light emitting diodes. They have good light-emitting properties and are easy to manufacture. The external quantum efficiency (the ratio of charge carriers emitted as light over all of those fed into the materials) of light-emitting diodes based on perovskites has until now been limited by defects that arise in the material during manufacture. The defects act as traps for the charge carriers and thus cause energy losses.
One way of dealing with defects is to add materials known as "passiviation molecules", which bind to the atoms that cause defects. The researchers had previously discovered a molecule with amino groups at its ends that gave a certain improvement in properties. However, when they selected a molecule that also contained oxygen atoms, the effect increased dramatically.
"We now understand that it is the hydrogen bonds between passivation molecules and perovskite materials that cause problems. This allowed us to search for a molecule that was perfect for passivation", says Feng Gao, senior lecturer in the Division of Biomolecular and Organic Electronics at Linköping University.
The molecule they found has two amino groups at its ends, with oxygen atoms at suitable distances between them. Oxygen atoms reduce the hydrogen bonding ability of amino groups, and hence increase the probability that they interact with defects. The number of traps for charge carriers in the perovskite is significantly reduced, allowing the charge carriers to recombine and emit light efficiently.
"This particular perovskite material gives highly efficient light-emitting diodes in the near-infrared region. Near-infrared light-emitting diodes are particularly useful for medical and telecommunication applications. We believe that our new findings can also be applied to perovskite light-emitting diodes with other colours", says Feng Gao.
The external quantum efficiency is a record-high 21.6%.
"We have developed the best light-emitting diodes in perovskite material yet. They can also compete with light-emitting diodes based on, for example, organic materials", says Wiedong Xu, postdoc in the Division of Biomolecular and Organic Electronics, LiU.
Share on:
Testimonial
"We’re proud to call I-Connect007 a trusted partner. Their innovative approach and industry insight made our podcast collaboration a success by connecting us with the right audience and delivering real results."
Julia McCaffrey - NCAB GroupSuggested Items
ITW EAE Despatch Ovens Now Support ASTM 5423 Testing
10/15/2025 | ITW EAEAs the demand for high-performance electrical insulation materials continues to grow—driven by the rapid expansion of electric vehicles (EVs) and energy storage systems—thermal processing has become a critical step in material development.
Beyond Thermal Conductivity: Exploring Polymer-based TIM Strategies for High-power-density Electronics
10/13/2025 | Padmanabha Shakthivelu and Nico Bruijnis, MacDermid Alpha Electronics SolutionsAs power density and thermal loads continue to increase, effective thermal management becomes increasingly important. Rapid and efficient heat transfer from power semiconductor chip packages is essential for achieving optimal performance and ensuring long-term reliability of temperature-sensitive components. This is particularly crucial in power systems that support advanced applications such as green energy generation, electric vehicles, aerospace, and defense, along with high-speed computing for data centers and artificial intelligence (AI).
Is Glass Finally Coming of Age?
10/13/2025 | Nolan Johnson, I-Connect007Substrates, by definition, form the base of all electronic devices. Whether discussing silicon wafers for semiconductors, glass-and-epoxy materials in printed circuits, or the base of choice for interposers, all these materials function as substrates. While other substrates have come and gone, silicon and FR-4 have remained the de facto standards for the industry.
Creative Materials to Showcase Innovative Functional Inks for Medical Devices at COMPAMED 2025
10/09/2025 | Creative Materials, Inc.Creative Materials, a leading manufacturer of high-performance functional inks and coatings, is pleased to announce its participation in COMPAMED 2025, taking place November 17–20 in Düsseldorf, Germany.
Jiva Leading the Charge Toward Sustainable Innovation
09/30/2025 | Marcy LaRont, PCB007 MagazineEnvironmental sustainability in business—product circularity—is a high priority these days. “Circularity,” the term meant to replace “recycling,” in its simplest definition, describes a full circle life for electronic products and all their elements. The result is re-use or a near-complete reintroduction of the base materials back into the supply chain, leaving very little left for waste. For what cannot be reused productively, the ultimate hope is to have better, less harmful means of disposal and/or materials that can seamlessly and harmlessly decompose and integrate back into the natural environment. That is where Jiva and Soluboard come in.