The Impact of Light Emitting Diodes

Abstract

The Electrochemical Society Interface • Winter 2015 • www.electrochem.org 43 T he Luminescence and Display Materials Division (LDM) was last featured in Interface in the winter 2009 issue. In that issue I wrote about the emerging technology of solid state lighting (SSL), which was then the subject of intensive research by many members of LDM. At that time, one envisioned the replacement of inefficient incandescent lamps by LED-based systems, leading to more than 3% reduction of energy consumption in the U.S., and accompanied by a similar reduction in pollution, greenhouse gases, and costs.1 It turns out that our predictions have been surpassed by recent developments in solid state lighting: the combined efforts of industry and academia, in conjunction with government support, have led to LED-based lighting devices, which are not only superior to incandescent lamp, but also to fluorescent lighting, the main light source in commercial and industrial applications. While high quality fluorescent lamps yield about 100 lumens/watt, hereby reaching the achievable potential for this technology, SSL devices have reached higher efficiencies already, with prototypes reaching 200 lumens/ watt.2 The importance of these rapid, and globally important, developments was recognized in 2014 by the Nobel Prize Committee, which awarded the Nobel Prize in Physics 2014 to Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura, “for the invention of efficient blue light-emitting diodes which has enabled bright and energysaving white light sources.”3 In this issue, Martin Hermus and Jakoah Brgoch report on recent approaches to develop efficient and stable phosphor materials in their article, “Phosphor by Design: Approaches Toward the Development of Advanced Luminescent Materials.” One would expect phosphor development to be an important research topic, but other aspects of SSL attract attention as well. The contribution “Polymeric Materials in Phosphor-Converted LEDs for Lighting Applications: Outlook and Challenges,” by Maxim Tchoul, Alan Piquette, and Alexander Linkov, addresses in detail the role of polymeric materials in solid state lighting, New technologies often have negative, unforeseen implications, and the article “Impact of Light Emitting Diode Adoption on Rare Element Use in Lighting: Implications for Yttrium, Europium, and Terbium Demand,” by Anthony Y. Ku, Anant A. Setlur, and Johnathan Loudis, addresses the question of possible shortages of critical rare earth elements. While the articles in this issue emphasize SSL, it should be noted that our LDM Division does (and should) provide a forum for all aspects of light-emitting processes and techniques for their implementation, and I find that advances in the different research areas often profit from the intellectual cross-fertilization among our members at the ECS meetings. Thus I hope to see you at PRiME 2016 in Honolulu.