My research investigates the optical properties of single semiconductor nanocrystals. Ensemble measurements of nanocrystals are broadened due to a distribution in particle size and limit the information obtainable about nanocrystal properties. By investigating single nanocrystals, insights into their photophysics have been achieved and new material properties have been observed, such as narrow emission linewidths and a "blinking" behavior of the photoluminescence. Lead salt (PbS, PbSe and PbTe) nanocrystals exhibit extreme quantum confinement and are expected to have significantly different physical properties than previously studied II-VI nanocrystals. Optical microscopy of single lead salt nanocrystals can provide new understanding of fundamental nanocrystal physics and will have implications for the use of these materials in future technological applications.
(top) STEM micrographs of PbSe QDs (bottom) Linear absorption spectra of PbSe QDs ranging in size from 3 to 8 nm.
