Rutgers Group Develops Rare Earth Free LED Phosphor
White LEDs are fast replacing conventional lighting sources, however, there are concerns that the rare earth materials used in their phosphors could become scarce and more expensive. White LEDs are made using a blue-emitting InGaN/GaN diode with a coating of a yellow-emitting phosphor such as cerium-doped yttrium aluminum garnet or (YAG):Ce3.
Scientists at Rutgers University in the US have now designed some new materials for making these yellow-emitting phosphors without rare earth elements. The group led by Jing Li has developed an inorganic-organic hybrid phosphor family made out of copper iodide, an abundant compound. They report their development in ACS' Journal of the American Chemical Society.
This family of I-VII binary semiconductor materials can be synthesised by a simple, low-cost solution process and are easily scalable, according to the group. Moreover band gap and emission energy, intensity, and colour can be systematically tuned by incorporating ligands with suitable electronic properties. High quantum efficiency is achieved for some of these compounds. Such features make this group of materials promising candidates as alternative phosphors for use in general lighting devices.
The group tuned the phosphors to glow a warm white shade or various other colors using a low-cost process.
"Combining these features, this material class shows significant promise for use in general lighting applications," they conclude.
AngelTech Live III: Join us on 12 April 2021!
AngelTech Live III will be broadcast on 12 April 2021, 10am BST, rebroadcast on 14 April (10am CTT) and 16 April (10am PST)
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Thanks to the great diversity of the semiconductor industry, we are always chasing new markets and developing a range of exciting technologies.
2021 is no different. Over the last few months interest in deep-UV LEDs has rocketed, due to its capability to disinfect and sanitise areas and combat Covid-19. We shall consider a roadmap for this device, along with technologies for boosting its output.
We shall also look at microLEDs, a display with many wonderful attributes, identifying processes for handling the mass transfer of tiny emitters that hold the key to commercialisation of this technology.
We shall also discuss electrification of transportation, underpinned by wide bandgap power electronics and supported by blue lasers that are ideal for processing copper.
Additional areas we will cover include the development of GaN ICs, to improve the reach of power electronics; the great strides that have been made with gallium oxide; and a look at new materials, such as cubic GaN and AlScN.
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