Shan J., van Veggel F.C.J.M., Raudsepp M., Pattantyus-Abraham A.G., Young J.F.
University of Victoria, CA
Keywords: colloidal quantum dots, colloidal synthesis, core/shell nanocrystals, infrared emission, photo-stability, type I, type II semiconductors
In an effort to improve photo-stability of IV-VI PbSe and PbS quantum dots (QDs) for application of infrared-based devices, we have synthesized type I core/shell colloidal QDs with PbSe and PbS as the cores, and SnSe and SnS as the shells. The new QDs were characterized by photoluminescence, HRTEM, XRD and EDX analysis. Absolute quantum yields and fluorescence time-life time were also measured. The improved photo-stability was demonstrated both in solution and solid state, and photo-bleaching tests upon irradiation of Xenon lamp. Core/shell QDs prevent PbSe or PbS from being oxidized and thus much less blue-shifting in emission than those of QDs without shells during the storage. When both core and core/shell QDs were subjected to the illumination of Xenon lamp (450 W), cores showed photo-bleaching within seconds; while core/shell QDs solutions have presented much more stable photo-stability and photoluminescence remained over minutes without significant degradation. These new type I core/shells will provide new opportunities for IV-VI PbSe and PbS QDs in the application of infrared devices
Journal: TechConnect Briefs
Volume: 3, Technical Proceedings of the 2006 NSTI Nanotechnology Conference and Trade Show, Volume 3
Published: May 7, 2006
Pages: 125 - 128
Industry sectors: Advanced Materials & Manufacturing | Sensors, MEMS, Electronics
Topics: Nanoelectronics, Photonic Materials & Devices
ISBN: 0-9767985-8-1