How Copper Makes Organic LEDs More Efficient
January 11, 2016 | Karlsruhe Institute of Technology (KIT)Estimated reading time: 3 minutes
Use of copper as a fluorescent material allows for the manufacture of inexpensive and environmentally compatible organic light-emitting diodes (OLEDs). Thermally activated delayed fuorescence (TADF) ensures high light yield. Scientists of Karlsruhe Institute of Technology (KIT), CYNORA, and the University of St Andrews have now measured the underlying quantum mechanics phenomenon of intersystem crossing in a copper complex. The results of this fundamental work are reported in the Science Advances journal and contribute to enhancing the energy efficiency of OLEDs.
Use of copper as a fluorescent material allows for the manufacture of inexpensive and environmentally compatible organic light-emitting diodes (OLEDs). Thermally activated delayed fuorescence (TADF) ensures high light yield. Scientists of Karlsruhe Institute of Technology (KIT), CYNORA, and the University of St Andrews have now measured the underlying quantum mechanics phenomenon of intersystem crossing in a copper complex. The results of this fundamental work are reported in the Science Advances journal and contribute to enhancing the energy efficiency of OLEDs.
Organic light-emitting diodes are deemed tomorrow's source of light. They homogeneously emit light in all observation directions and produce brilliant colors and high contrasts. As it is also possible to manufacture transparent and flexible OLEDs, new application and design options result, such as flat light sources on window panes or displays that can be rolled up. OLEDs consist of ultra-thin layers of organic materials, which serve as emitter and are located between two electrodes. When voltage is applied, electrons from the cathode and holes (positive charges) from the anode are injected into the emitter, where they form electron-hole pairs. These so-called excitons are quasiparticles in the excited state. When they decay into their initial state again, they release energy.
Excitons may assume two different states: Singlet excitons decay immediately and emit light, whereas triplet excitons release their energy in the form of heat. Usually, 25 percent singlets and 75 percent triplets are encountered in OLEDs. To enhance energy efficiency of an OLED, also triplet excitons have to be used to generate light. In conventional light-emitting diodes heavy metals, such as iridium and platinum, are added for this purpose. But these materials are expensive, have a limited availability, and require complex OLED production methods.
Page 1 of 2
Suggested Items
The Chemical Connection: Reducing Etch System Water Usage, Part 2
05/02/2024 | Don Ball -- Column: The Chemical ConnectionIn my last column, I reviewed some relatively simple ways to reduce water usage in existing etch systems: cutting down cooling coil water flow, adding chillers to replace plant water for cooling, lowering flow rate nozzles for rinses, etc. This month, I’ll continue with more ways to control water usage in your etcher. Most of these are not easily retrofittable to existing equipment but should be given serious consideration when new equipment is contemplated. With the right combination of add-ons, it is possible to bring the amount of water used in an etch system to almost zero.
Designer’s Notebook: What Designers Need to Know About Manufacturing, Part 2
04/24/2024 | Vern Solberg -- Column: Designer's NotebookThe printed circuit board (PCB) is the primary base element for providing the interconnect platform for mounting and electrically joining electronic components. When assessing PCB design complexity, first consider the component area and board area ratio. If the surface area for the component interface is restricted, it may justify adopting multilayer or multilayer sequential buildup (SBU) PCB fabrication to enable a more efficient sub-surface circuit interconnect.
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.
ENNOVI Introduces a New Flexible Circuit Production Process for Low Voltage Connectivity in EV Battery Cell Contacting Systems
04/03/2024 | PRNewswireENNOVI, a mobility electrification solutions partner, introduces a more advanced and sustainable way of producing flexible circuits for low voltage signals in electric vehicle (EV) battery cell contacting systems.
Heavy Copper PCBs: Bridging the Gap Between Design and Fabrication, Part 1
04/01/2024 | Yash Sutariya, Saturn Electronics ServicesThey call me Sparky. This is due to my talent for getting shocked by a variety of voltages and because I cannot seem to keep my hands out of power control cabinets. While I do not have the time to throw the knife switch to the off position, that doesn’t stop me from sticking screwdrivers into the fuse boxes. In all honesty, I’m lucky to be alive. Fortunately, I also have a talent for building high-voltage heavy copper circuit boards. Since this is where I spend most of my time, I can guide you through some potential design for manufacturability (DFM) hazards you may encounter with heavy copper design.