Development of a High Precision Quantum Dot Synthesis Method Utilizing a Microfluidic Reactor and In-Line Fluorescence Flow Cell

<p>Quantum dots show great potential for use as spectral converters in solar cells, lighting applications, and biological imaging. These applications require precise control of quantum dot size to maximize performance. The quality, size, and fluorescence of quantum dots depend on parameters that are difficult to control using traditional batch synthesis processes. An alternative, high precision process was developed for the synthesis of cadmium-selenide quantum dots using a microfluidic reactor and fluorescence flow cell. The process required creating separate cadmium and selenium precursors that were then mixed in a nitrogen environment at 17°C. Using an NE-300^® syringe pump, the solution was pumped through a microfluidic reactor submerged in a 240°C oil bath. The reactor then fed through a water quench bath at 25°C to terminate the nucleation and growth reaction. The fluorescence profiles of the quantum dot solutions were then characterized with an in-line fluorescence flow cell used in conjunction with an Ocean Optics^® USB4000^® spectrometer and a ThorLabs^® LED UV light source. Flow rates through the reactor were varied from 0.05ml/min to 2ml/min. A central peak wavelength was registered in the fluorescence profiles for each flow rate. Monodisperse Cd-Se quantum dot solutions were synthesized across a broad spectrum of wavelengths ranging from 490nm to 620nm. An empirical relationship between flow rate and center wavelength was determined.</p>

Name thesis:degree_name

MS in Engineering - Materials Engineering

Discipline thesis:degree_discipline

Materials Engineering

Year dc:date.available

2014

Author dc:creator

• Lafferty, William Henry

Contributors dc:contributor

• Richard Savage

• Quantum Dots
• Microfluidics
• Fluorescence
• Flow Cell
• Cadmium-Selenide
• Semiconductor and Optical Materials

Identifier

10.15368/theses.2014.165

OAI identifier oai:identifier

oai:digitalcommons.calpoly.edu:theses-2416