Allison Dennis

Synthesis and Characterization of Thick-shelled InP/ZnSe Quantum Dots

PROJECT DESCRIPTION
Quantum dots (QDs) are semiconductor nanoparticles that emit distinct colors of light following UV illumination. Core/shell QDs have one semiconductor material coated by a protective layer of a second semiconductor. We have recently discovered that putting thick layers of the protective shell on the core material can produce dramatically improved optical properties. We are interested in making non-toxic visible emitters by coating indium phosphide (InP) with zinc selenide (ZnSe). The synthesis of these particles requires colloidal synthesis of the InP cores and the deposition of the ZnSe shell one monolayer at a time through successive ion layer adsorption and reaction (SILAR).

LEARNING GOALS
• Learn standard inorganic chemistry techniques that are adapted for nanomaterials chemistry, including air-free hot injection chemistry using Schlenk technique.
• The role of ligands in controlling reaction rates and balancing kinetic and thermodynamic drivers of the reaction will be discussed as the reaction parameters are optimized.
• Use precipitation as a primary means of cleaning the QDs and optical characterization will include absorption and fluorescence spectroscopy and absolute quantum yield measurements using an integrating sphere.
• Understand the fundamentals of quantum confinement and bandgap engineering as it applies to QD emission.

Learn more about Professor Dennis‘ work at her lab website.