- A brief history of solid state lighting

Early Years

The first LED devices were developed in the 1960s, however at the time they were inefficient, costly and produced very little light. Over the years the technology was developed further and in 2000 Haitz et al.[1] presented the observation that the development was exponential and doubled efficiency and light output every 3 years. When such a development is seen, the first increases in performance can seem insignificant. A doubling of a very little light output is still very little light, but as the doubling continued, the technology began to break into new fields, from scientific instrumentation to indicators lights on household electronics to electrical children’s toy. The breakthrough came in the 1990s when the blue LED was developed, by Nakamura and others. They received the Nobel prize for it and this single component certainly has changed the field of lighting in very dramatic ways[2]. With the efficient and high light output  mblue LED, came the phosphor converted white LED, the technology that could move LED from indicator lights and toys to general lighting – and application that consume about 15% of the worlds total electricity production.

Lighting at DTU Fotonik

The possibilities of LED technology in a Danish context were realized by Paul Micheal Petersen and Carsten Dam-Hansen when working at Risø National Laboratory for Sustainable Energy.  In 2004 they initiated the first Danish research and development project on LED in Denmark EDI, funded by ELFORSK, in order to demonstrate the potential of the technology, and lay out the ground work for the innovation that would need to be done by Danish industry, for when LED lighting would take center stage. In 2008 the optics program and the optical activities within The Technical University of Denmark was merged to form DTU Fotonik.