UCSB researchers reveal phosphor-free white LEDs and separately new light extraction technique (UPDATED)

GaN-substrate LEDs with blue and yellow quantum wells deliver white light with no phosphor conversion while another UCSB project involves nanorod structures to improve light extraction in LEDs.

Researchers from the University of California at Santa Barbara (UCSB) have published two new LED research papers in scientific journals. Both of the papers have LED pioneer Shuji Nakamura as a co-author and one is focused on using gallium nitride (GaN) substrates and a novel epitaxial approach to grow blue and yellow quantum wells (QWs), thereby eliminating the need for phosphor to yield white light. The second paper describes nanoscale structural techniques that can increase light extraction in packaged LEDs and greatly narrow the beam angle.

We don’t regularly cover research until it nears a commercial stage, but UCSB has been critical in advancing the science of white LEDs, solid-state lighting (SSL) efficiency and quality, and technology for lamps and luminaires. Indeed, Nakamura moved from Nichia to UCSB more than a decade ago to continue advancement in white LED technology and headed the university’s Solid State Lighting and Energy Center (SSLEC) when it was formed back in 2007. Nakamura would go on to later co-found Soraa with the goal of improving LED light quality and efficacy using homogeneous GaN substrates to grow GaN epitaxial layers. The company came into the public eye at our Strategies in Light conference in 2012.