Gwangju Institute of Science and Technology

Gwangju Institute of Science and Technology Researchers Demonstrate Improved Performance of Transition Metal Oxide Based Organic Photovoltaics

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Tuesday, October 18, 2022

GWANGJU, South Korea, Oct. 18, 2022 /PRNewswire/ -- Harnessing the power of the sun and converting it into electricity using photovoltaic solar cells is one of the top contenders for combating the current energy crisis. To this end, researchers have developed organic photovoltaics (OPVs) with transition metal oxide (TMO) thin-film interfacial layers as a cost-effective alternative to commercial silicon solar cells. OPVs are known for their excellent photochemical properties and low-cost mass producibility. However, the TMO layer often suffers from a degraded electrical conductivity owing to the presence of lingering organic metal-binding ligands generated during their synthesis. This greatly limits the OPVs from reaching their full potential.

Key Points: 
  • To this end, researchers have developed organic photovoltaics (OPVs) with transition metal oxide (TMO) thin-film interfacial layers as a cost-effective alternative to commercial silicon solar cells.
  • However, the TMO layer often suffers from a degraded electrical conductivity owing to the presence of lingering organic metal-binding ligands generated during their synthesis.
  • A team of researchers led by Prof.Kwanghee Lee from Gwangju Institute of Science and Technology, Korea found a way to overcome this challenge.
  • Further, the inverted OPV configuration showed 17.6% improved efficiency, with over 70% retention of the initial efficiency for up to 100 hours.

Gwangju Institute of Science and Technology Researchers Design Durable Organic Semiconductor Photocathodes with Metal Foil Encapsulation

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Friday, September 23, 2022

GWANGJU, South Korea, Sept. 23, 2022 /PRNewswire/ -- Hydrogen is emerging as a popular eco-friendly alternative to fossil fuel resources owing to its carbon-neutral combustion products (water, electricity, and heat) and is considered to be the next-generation fuel for a zero-emission society. However, the major source of hydrogen is, ironically, fossil fuels.

Key Points: 
  • One way to produce hydrogen in a clean and sustainable manner is through water splitting driven by sunlight.
  • The process, known as "photoelectrochemical (PEC) water splitting" is the basis of operation of organic photovoltaic cells.
  • Now, a team of researchers led by Prof. Sanghan Lee from Gwangju Institute of Science and Technology, Korea, may have finally solved this problem.
  • The team fabricated an organic photovoltaic cell, in which the OS photocathode was covered with titanium foil and well-dispersed platinum nanoparticles.

Researchers from Gwangju Institute of Science and Technology Develop a New Method for Denoising Images

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Tuesday, September 20, 2022

GWANGJU, South Korea, Sept. 20, 2022 /PRNewswire/ -- High-quality visual displays rendered using the "path tracing" algorithm are often noisy. Recent supervised learning-based denoising algorithms rely on external training dataset, take long to train, and do not work well when the training and test images are different. Now, researchers from Gwangju Institute of Science and Technology, VinAI Research and University of Waterloo have put forth a novel self-supervised post-correction network that improves the denoising performance without relying on a reference. 

Key Points: 
  • Recent supervised learning-based denoising algorithms rely on external training dataset, take long to train, and do not work well when the training and test images are different.
  • Now, researchers from Gwangju Institute of Science and Technology, VinAI Research and University of Waterloo have put forth a novel self-supervised post-correction network that improves the denoising performance without relying on a reference.
  • High-quality computer graphics, with their ubiquitous presence in games, illustrations, and visualization, are considered state-of-the-art in visual display technology.
  • The method used to render high-quality and realistic images is known as "path tracing," which makes use of a Monte Carlo (MC) denoising approach based on supervised machine learning.

Gwangju Institute of Science and Technology Researchers Pave the Way for Large-scale, Efficient Organic Solar Cells with Water Treatment

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Friday, September 16, 2022

GWANGJU, South Korea, Sept. 16, 2022 /PRNewswire/ -- Organic solar cells (OSCs), which use organic polymers to convert sunlight into electricity, have received considerable attention in recent times for their desirable properties as next-generation energy sources. These include lightweight, flexibility, scalability, and a high power conversion efficiency (>19%). Currently, several strategies exist for enhancing the performance and stability of OSCs. However, a problem that lingers on is the difficulty of controlling the morphology of the active layer in OSCs when scaling up to large areas. This makes it challenging to obtain high-quality active layer thin films and, in turn, fine-tune the device efficiency.

Key Points: 
  • However, a problem that lingers on is the difficulty of controlling the morphology of the active layer in OSCs when scaling up to large areas.
  • This makes it challenging to obtain high-quality active layer thin films and, in turn, fine-tune the device efficiency.
  • In a recent study, a team of researchers from the Gwangju Institute of Science and Technology, Korea set out to address this issue.
  • The active solution was hydrophobic and, accordingly, the researchers decided to use deionized (DI) water and vortices to stir the solution.

GIST Scientists Develop Model that Adjusts Videogame Difficulty Based on Player Emotions

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Tuesday, September 6, 2022

GWANGJU, South Korea, Sept. 6, 2022 /PRNewswire/ -- Appropriately balancing a videogame's difficulty is essential to provide players with a pleasant experience. In a recent study, Korean scientists developed a novel approach for dynamic difficulty adjustment where the players' emotions are estimated using in-game data, and the difficulty level is tweaked accordingly to maximize player satisfaction. Their efforts could contribute to balancing the difficulty of games and making them more appealing to all types of players. 

Key Points: 
  • In a recent study, Korean scientists developed a novel approach for dynamic difficulty adjustment where the players' emotions are estimated using in-game data, and the difficulty level is tweaked accordingly to maximize player satisfaction.
  • Their efforts could contribute to balancing the difficulty of games and making them more appealing to all types of players.
  • The idea of DDA is to adjust the difficulty of a game in real-time according to player performance.
  • For example, if player performance exceeds the developer's expectations for a given difficulty level, the game's DDA agent can automatically raise the difficulty to increase the challenge presented to the player.

Gwangju Institute of Science and Technology Scientists Realize Large-Area Organic Solar Cells that are Low-cost, Flexible, and Efficient

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Wednesday, August 17, 2022

GWANGJU, South Korea, Aug. 17, 2022 /PRNewswire/ -- Organic solar cells (OSCs), which make use of organic materials to convert sunlight into electricity, are an attractive candidate for future photovoltaics. This is due to several of their desirable features, such as their light weight, flexibility, malleability, and, most importantly, high power conversion efficiency (PCE). Such qualities make them ideal for a wide range of applications.

Key Points: 
  • GWANGJU, South Korea, Aug. 17, 2022 /PRNewswire/ --Organic solar cells (OSCs), which make use of organic materials to convert sunlight into electricity, are an attractive candidate for future photovoltaics.
  • Most OSCs are produced using a technique called "spin coating," which allows for high PCEs but makes for poor scalability.
  • This is where Dr. Hongkyu Kang and Prof. Kwanghee Lee from the Gwangju Institute of Science and Technology (GIST) in Korea come in.
  • This makes it easier to use ZnO for manufacturing organic solar cells and developing a printing technology for large-area solar cell technology,"says Dr. Kang.

Gwangju Institute of Science and Technology Scientists Develop a Universal Method for Improving the Lifespan of Lithium-Ion Batteries

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Friday, August 12, 2022

GWANGJU, South Korea, Aug. 12, 2022 /PRNewswire/ -- The advent of electric vehicles has given rise to the demand for lithium-ion batteries with high energy densities. This has led to the development of anodes with large charge storage capacity. Unfortunately, this storage capacity tends to degrade over multiple charge/discharge cycles, reducing the battery life.

Key Points: 
  • The short battery life results from an irreversible volume change in the anode during cycling, which causes degradation of electrical contacts and structural collapse.
  • During charging, lithium ions move from the cathode and combine with the nanoparticles in the anode.
  • While the researchers used a silicon anode, the developed method is applicable to other anode materials, such as Sn, Sb, Al and Mg.
  • Moreover, the anodes can be modified regardless of how they were manufactured, making it a universally applicable method for improving battery life.

Gwangju Institute of Science and Technology Scientists Improve the Power Output of Triboelectric Nanogenerators with Carbon Particles

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Wednesday, August 10, 2022

GWANGJU, South Korea, Aug. 10, 2022 /PRNewswire/ -- Most of us have felt the shock from static electricity by touching a metallic object after putting on a sweater or walking across a carpet. This occurs as a result of charge build-up whenever two dissimilar materials (such as our body and the fabric) come in contact with each other. 

Key Points: 
  • In 2012, scientists from the USA and China used this phenomenon, known as "triboelectric effect," to build a triboelectric nanogenerator (TENG) that converts unused mechanical energy into useful electrical energy.
  • Viewed as potential sustainable energy harvesters, efforts have been made to enhance the power output of TENGs by injecting charges to the surface of triboelectric films.
  • However, charge recombination in the electrode and charge repulsion on the surface of the material prevents them from achieving high surface charge densities.
  • To make the layers, the researchers used electrospun mesoporous carbon spheres together with layers of polyvinylidene fluoride (PVDF) and nylon.

Fiddler Crab Eye View Inspires Gwangju Institute of Science and Technology Researchers to Develop Novel Artificial Vision

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Tuesday, August 2, 2022

GWANGJU, South Korea, Aug. 2, 2022 /PRNewswire/ -- Artificial vision systems are implemented in motion sensing, object detection, and self-driving vehicles. However, they are not suitable for changing external environments and are limited to a hemispherical field-of-view (FOV). Addressing this issue, researchers from GIST have now developed a novel artificial vision with 360° FOV that can image both terrestrial and aquatic environments.The system, modeled after the eye structure of the fiddler crab, could help realize the all-weather vision and panoramic object detection.

Key Points: 
  • GWANGJU, South Korea, Aug. 2, 2022 /PRNewswire/ -- Artificial vision systems are implemented in motion sensing, object detection, and self-driving vehicles.
  • Addressing this issue, researchers from GIST have now developed a novel artificial vision with 360 FOV that can image both terrestrial and aquatic environments.The system, modeled after the eye structure of the fiddler crab, could help realize the all-weather vision and panoramic object detection.
  • Artificial vision systems find a wide range of applications, including self-driving cars, object detection, crop monitoring, and smart cameras.
  • For instance, human and insect vision have inspired terrestrial artificial vision, while fish eyes have led to aquatic artificial vision.

Gwangju Institute of Science and Technology Researchers Improve the Scanning Capability of Magnetic Particle Imaging Systems Used for Medical Imaging

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Friday, July 22, 2022

GWANGJU, South Korea, July 22, 2022 /PRNewswire/ -- Magnetic particle imaging (MPI) is an emerging imaging modality that is based on the detection of superparamagnetic iron oxide nanoparticles that have been injected into the body. The magnetic particles act like tracers and are detected in response to a moving magnetic field free point (FFP), which changes their magnetic direction. As these particles do not naturally exist in the human body, it makes MPI highly sensitive and free from background noise. MPI could potentially transform medical imaging. However, currently available commercial scanners often compromise between coverage volume and imaging resolution.

Key Points: 
  • The magnetic particles act like tracers and are detected in response to a moving magnetic field free point (FFP), which changes their magnetic direction.
  • As these particles do not naturally exist in the human body, it makes MPI highly sensitive and free from background noise.
  • In a new study published online on 29 April 2022 in IEEE Transactions on Industrial Electronics , researchers from Gwangju Institute of Science and Technology (GIST) in South Korea have now addressed this issue.
  • Authors: Tuan-Anh Le*, Minh Phu Bui, and Jungwon Yoon*
    Affiliations: Gwangju Institute of Science and Technology, the Republic of Korea