Bright Cd-Free Quantum Dots for Wide Color Gamut QLED TVs

Hyosook Jang, and Eunjoo Jang
Research Master, Principal Researcher, Ph.D.
Samsung Advanced Institute of Technology (SAIT), Samsung Electronics Co., Suwon, Korea


Quantum dots (QDs) have taken the spotlight as light-emitting materials for the next generation displays because of their color tunability, narrow emission and high quantum efficiency. Despite of the superior performance of Cd-based QDs, the toxicity problem has restricted their commercial prosperity and it has been requested to develop environmentally friendly alternatives showing the better qualities. InP-based QDs have been actively studied as the most promising eco-friendly QDs. However, it was very difficult to synthesize InP QDs without surface defects due to the nature that is easy to be oxidized. Also, the large size distribution of InP QDs causes broad emission spectrum and the poor color purity. We achieved Cd-free QDs of high luminescence efficiency (> 90%) and narrow bandwidth (< 40 nm) simultaneously by controlling the oxidized interface and narrowing their size distribution. This impressive outcome is applied into QLED TVs for the first time and they show the superior color reproducibility of DCI 99% and color volume 100% and comparable brightness with Cd-based QDs.