high performance

LEDs have become the standard source of energy-efficient lighting. They make use of semiconductors to turn electricity into light. Depending upon the materials used to make them, LEDs produce different colors. In the early 1990s, the first blue LEDs were discovered, ultimately earning the Nobel Prize in physics, and enabling LEDs to produce white light, which is essential for general lighting applications.

Blue LEDs have shortcomings. Some have issues with stability, scalability, cost, efficiency, complexity in manufacturing, or have environmental concerns because of the use of toxic components.

Researchers at Rutgers University in collaboration with scientists at several other institutions have found a way to make blue LEDs more efficient and sustainable. These LEDs use a new type of hybrid material that is a combination of copper iodide with organic molecules. The impressive performance of these LEDs was achieved through an innovative technique called dual interfacial hydrogen-bond passivation. This new manufacturing technique boosts the performance of LEDs by a factor of four.

The material has several advantages. It has a very high photoluminescence quantum yield, which means that it converts nearly all the photoenergy it receives into blue light. The LEDs last longer than many others and they work well in larger-scale applications, maintaining high efficiency. The materials are eco-friendly and cost-effective.

According to the researchers, this new approach could be a versatile strategy for generating high-performance LEDs that can pave the way for better, brighter, and longer-lasting LEDs.

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Scientists Develop Deep-Blue LEDs Expected to Greatly Enhance General Lighting

Photo, posted February 1, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

There are various ways to generate renewable energy from the world’s oceans, most obviously from the power of tides and waves. But there is also an oceanic energy source called osmotic or “blue” energy. Osmotic energy uses the differences in pressure and salinity between freshwater and saltwater to generate electricity.

When freshwater and saltwater are mixed together, large amounts of energy are released. If the freshwater and seawater are then separated via a semi-permeable membrane, the freshwater will pass through the membrane and dilute the saltwater due to the chemical potential difference. This process is called osmosis. If the salt ions are captured completely by the membrane, the passing of water through the membrane will create a pressure known as osmotic pressure. This pressure can be used to generate electricity by using it to drive a turbine. This has been demonstrated to work as far back as the 1970s, but the materials we have to use are not adequate to withstand ocean conditions over the long term and tend to break down quickly in the water.

New research, published in the journal Joule, looked to living organisms for inspiration to develop an improved osmotic energy system. Scientists from the U.S. and Australia combined multiple materials to mimic the kind of high-performance membranes that are found in living organisms. They created a hybrid membrane made from aramid microfibers (like those used in Kevlar) and boron nitride. The new material provides both the flexibility of cartilage and the strength and stability of bone.

The researchers believe that the low cost and high stability of the new hybrid membrane will allow it to succeed in volatile marine environments. They also expect the technology will be both efficient and scalable.

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Inspired by the Tissues of Living Organisms, Researchers Take One Step Closer to Harvesting “Blue Energy”

Photo, posted February 14, 2017, courtesy of Marian May via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Better blue LEDs

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Harvesting Blue Energy | Earth Wise

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