Silicon compatible laser based on colloidal quantum dots

Research Area: Heterogeneous Integration with Silicon Photonics

Main Researcher: Bram De Geyter

A cheap, reliable and robust light source integrated on silicon is often identified as a major missing link in silicon photonics research. We are using a different approach than usual by depositing colloidal quantum dots, produced in suspension through wet chemical synthesis. These quantum dots have a very efficient photoluminescence and can be tuned to a specific emission wavelength by controlling their size.

TEM image of a colloidal PbSe nanocrystal

The synthesis of these IV-VI nanocrystals (PbSe, PbS, PbTe) has been perfected at the Physics and Chemistry of Nanostructures Group. Further development of core/shell nanocrystals is ongoing, coating the PbX quantum dots with the higher bandgap CdX (X=Se,S,Te). This stabilizes the luminescence and resolves oxidation problems. Furthermore engineering is being done to develop a core/shell quantum dot with staggered or type-II band alignment. These have very promising properties like ultra-low threshold for lasing applications.

Other people involved:

• Weiqiang Xie
• Bram De Geyter
• Pieter Geiregat

Publications

International Journals


1. B. De Geyter, Houtepen, Arjan J., Carrillo, Sergio, P. Geiregat, Gao, Yunan, Ten Cate, Sybren, Schins, Juleon M., D. Van Thourhout, Delerue, Cristophe, Siebbeles, Laurens D.A., Hens, Zeger, Broadband and Picosecond Intraband Relaxation in Lead-Based Colloidal Quantum Dots,ACS Nano, 6(7), p.6067–6074 (2012)  .
2. Yolanda Justo, Bart Goris, John Sundar Kamal, P. Geiregat, Sara Bals, Zeger Hens, Multipe Dot-in-Rod PbS/CdS Heterostructures with High Photoluminescence Quantum Yield in the Near-Infrared,Journal of the American Chemical Society, 134(12), p.5484–5487 (2012)  .
3. I. Moreels, B. De Geyter, D. Van Thourhout, Z. Hens, Transmission of a quantum-dot-silicon-on-insulator hybrid notch filter,Journal of the Optical Society of America B-Optical Physics, 26(6), p.1243-1247 (2009)  .
4. K. Lambert, B. De Geyter, I. Moreels, Z. Hens, PbTe|CdTe core|shell particles by cation exchange, a HR-TEM study,Chemistry of Materials, 21(5), p.778-780 (2009)  .