Discovering a New Class of Materials for Making LEDs
July 20, 2015 | UCLA NewsroomEstimated reading time: 1 minute
Over the last decade, advances in the technology of light-emitting diodes, or LEDs, have helped to improve the performance of devices ranging from television and computer screens to flashlights. As the uses for LEDs expand, scientists continue to look for ways to increase their efficiency while simplifying how they are manufactured.
A new study by researchers from the California NanoSystems Institute at UCLA is the first demonstration of electroluminescence from multilayer molybdenum disulfide, or MoS2, a discovery that could lead to a new class of materials for making LEDs. The study, led by Xianfeng Duan, professor of chemistry and biochemistry, was published in the journal Nature Communications on July 1, 2015.
In its single-layer form, molybdenum disulfide is optically active, meaning that it emits light when electric current is run through it or when it is shot with a nondestructive laser. Multilayer molybdenum disulfide, by contrast, is easier and less expensive to produce, but it is not normally luminescent. In the new study, Duan and first author Dehui Li, a postdoctoral scholar in Duan’s lab, created the first multilayer molybdenum disulfide device that shows strong luminescence when electrical current is passed through it.
“We were trying to make a vertically stacked light-emitting device based on monolayer MoS2, but it was difficult to get the efficiency as high as we wanted,” Duan said. “On the other hand, it was rather surprising for us to discover that similar vertical devices made of multilayer MoS2 somehow showed very strong electroluminescence, which was completely unexpected since the multilayer MoS2 is generally believed to be optically inactive. So we followed this new lead to investigate the underlying mechanism and the potential of multilayer MoS2 in light-emitting devices.”
Duan and his team used a technique called electric field-induced enhancement, which relocates the electrons from a dark state to a luminescent state, thereby increasing the material’s ability to convert electrons into light particles, or photons. With this technique, the multilayer MoS2 semiconductors are at least as efficient as monolayer ones.
Duan’s team is currently moving forward to apply this approach to similar materials, including tungsten diselenide, molybdenum diselenide and tungsten disulphide, with the goal of helping to create a new generation of light-emitting devices from two-dimensional layered materials, which are less expensive and easier to use in manufacturing.
Suggested Items
SMC Korea 2024 to Highlight Semiconductor Materials Trends and Innovations on Industry’s Path to $1 Trillion
04/24/2024 | SEMIWith Korea a major consumer of semiconductor materials and advanced materials a key driver of innovation on the industry’s path to $1 trillion, industry leaders and experts will gather at SMC (Strategic Materials Conference) Korea 2024 on May 29 at the Suwon Convention Center in Gyeonggi-do, South Korea to provide insights into the latest materials developments and trends. Registration is open.
Groundbreaking Ceremony Marks the Beginning of a New Era for Newccess Industrial; The Construction of the MINGXIN Building
04/12/2024 | Newccess IndustrialOn a clear and sunny day in March, the groundbreaking ceremony for the MINGXIN Building took place in Shenzhen, China. This moment marked the official commencement of construction for a project that will reshape the semiconductor materials industry.
The Need for a Holistic Global Sustainability Standard
04/10/2024 | Michael Ford, Aegis SoftwareNo one can deny that the resources of our fragile planet are finite. The environment seems like a third party, subject to constant degradation. We’re acutely aware of the effects of pollution on our climate, and despite our “throw-away” culture, recycling and recovery of materials has remained relatively expensive, even as we use more energy just to survive.
iNEMI Publishes Four Roadmap Topics
04/04/2024 | iNEMIThe International Electronics Manufacturing Initiative (iNEMI) announces the availability of the first roadmap topics in the new iNEMI Roadmap format. Printed circuit boards, sustainable electronics, smart manufacturing, and mmWave materials and test are now available online.
Insulectro’s 'Storekeepers' Extend Their Welcome to Technology Village at IPC APEX EXPO
04/03/2024 | InsulectroInsulectro, the largest distributor of materials for use in the manufacture of PCBs and printed electronics, welcomes attendees to its TECHNOLOGY VILLAGE during this year’s IPC APEX EXPO at the Anaheim Convention Center, April 9-11, 2024.