Synthesis and Characterization of CdSe Quantum Dots

In this lesson, students will synthesize and characterize CdSe quantum dots. The lesson will introduce students to semiconductor quantum dots. Students will explore how surfactant-based chemistry can be used to synthesize CdSe quantum dots and examine how the size of the quantum dots can be controlled by varying reaction time. The laboratory will demonstrate how the color of these quantum dots can be connected to the size of the nanoparticle by considering the electrons as freely moving particles in a box with the dimensions of the nanoparticle. The model of the free particle will be compared with more exact results, where the particle sizes were measured from scanning electron microscopy, and use this to create a calibration curve. Students will be able to estimate the size of quantum dots by using UV-VIS absorption spectroscopy. An alternative to the bench top spectrometer used in this lesson it to remotely access one on the Remotely Accessible Instruments in Nanotechnology (RAIN) which has three instruments for student use. Visit: https://www.nano4me.org/remoteaccess