Berlin 2018 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 88: Gerhard Ertl Young Investigator Award
O 88.4: Invited Talk
Thursday, March 15, 2018, 12:00–12:30, MA 005
Tuning optoelectronic properties of silicon quantum dots via surface chemistry — •Mita Dasog1,2,3, Jonathan G. C. Veinot2, and Nathan S. Lewis3 — 1Department of Chemistry, Dalhousie University, Halifax, NS, Canada — 2Department of Chemistry, University of Alberta, Edmonton, AB, Canada — 3Division of Chemistry and Chemistry Engineering, California Institute of Technology, Pasadena, CA, United States
Over the last thirty years, quantum dots have become an indispensable tool for optoelectronic applications. The optical properties of colloidal quantum dots can be tuned through their size and shape. Among them silicon quantum dots (Si-QDs) have attracted attention due to their natural abundance and bio-compatibility. While few reports exist on size dependent emission from Si-QDs, the vast majority of them defy quantum confinement effect. In this talk, surface chemistry methodologies and luminescence in Si-QDs originating from surface states will be discussed. It was discovered that the emission can be tuned across the visible spectrum by changing the surface groups. The blue-to-green emission originating from oxynitride defect-states have shorter excited lifetimes and higher emission quantum yields compared to the bandgap emission in Si-QDs and the yellow-to-orange emission can originate from suboxide defect-states and have longer excited lifetimes and lower emission quantum yields. The Si-QDs can be further functionalized with surface molecules for bioimaging and explosives sensing.