Boston Chapter of the IEEE Photonics Society

Abstract:  When shrinking a bulk semiconductor material to the size of a nanocrystal, several properties of the material change due to a phenomenon called quantum confinement.  One of the consequences of quantum confinement is that the band gap of the semiconductor can be precisely tuned by controlling the average size of the crystals.  These quantum dots (QDs) have unique properties as they are broad-band absorbers, narrow emitters, and in many cases have near-unity quantum yield.  By efficiently converting bluer light into redder light, QDs have already been used in lighting products, and show potential to be adopted into liquid crystal display products in the near future.  

Another application for QDs is to function as the emissive layer of a light emitting diode.  These quantum dot light emitting devices (QLEDs) are an emerging class of thin-film hybrid organic-inorganic structures, which could potentially achieve best-in-class performance amongst large-area emissive light sources.  In this presentation, we will present recent advancements in both device design and materials performance that has enabled QLEDs to achieve near-unity internal quantum efficiency.  In addition, we will discuss QD printing methods that have allowed the creation of active matrix QLED displays.

Biography:  Charles Hamilton is a member of the chemistry team at QD Vision where he currently leads the electroluminescent materials development group.  Dr. Hamilton received his Ph.D. in inorganic chemistry from the Massachusetts Institute of Technology in Jan. 2007.  There he worked primarily on homogeneous catalyst synthesis, development and mechanistic studies.  After MIT, Dr. Hamilton received a post-doctoral position at Los Alamos National Laboratory applying his knowledge of synthetic chemistry to activate chemical hydrogen storage materials.  Through funding of the DOE’s chemical hydrogen storage center of excellence, his advances made it possible to use cheap iron-based catalysts instead of expensive noble metal-based catalysts greatly increasing the practicality of a chemical hydrogen storage system.  In Dec. 2008, Dr. Hamilton accepted a senior chemist position at QD Vision.  Since then, he has been focused on material development in support of various applications, especially quantum dot light-emitting devices.

Location:  MIT Lincoln Laboratory