This is an annual report by the U.S. Department of Energy on the current state of SSL. Published in January 2019, it looks back on the year 2018 – examining how a new understanding of lighting science opens up possibilities to further reduce energy consumption and improve lighting performance in new ways. LED and OLED applications are discussed, along with associated R&D challenges and funding activities. This paper is relevant for academic, investment/financing, government, technology, and utility and business leaders.
Key words: R&D, solid-state lighting, LED, OLED