Paul Alivisatos

Professor Paul Alivisatos, University of California. "Towards a new generation of quantum dots with luminescence efficiency approaching the theoretical limit of quantum yield." Student-hosted talk.

Abstract:  Colloidal quantum dots are now routinely used for their bright and color tunable luminescence in areas as diverse as biological imaging and television displays. These applications require a high luminescence quantum yield, typically in the 0.85 to 0.95 range, which already requires a high degree of control over structure and non-radiative defects in the dots. This talk will discuss what might happen if we could prepared quantum dots with luminescence efficiencies that logartithmically approach unity. Such nearly perfect luminophores could be used to focus light more tightly than any geometric lens as may lead to the creation of energy conversion devices of interest. Making them may require new methods for measuring quantum yields and for observing and controlling the structure within a nanocrystal at the atomic level.