The Surface Chemistry of Quantum Dots
Semester: Fall 2024
Faculty Advisor: Xuemei M. Cheng
Field Site: Massachusetts Institute of Technology
Field Supervisor: Eliza K. Price
Praxis Poster:
Rogatch, Angeilna - Praxis_Poster_Final
Further Context:
This semester, I worked remotely with the Tisdale Lab in the Department of Chemical Engineering at MIT. My project was an extension of my on-site MIT Summer Research Program (MSRP) internship. The Tisdale Lab focuses on developing nanoscale materials and exploring their applications in energy conversion and optoelectronics.
Our work centered on a novel material called quantum dots (QDs) – tiny semiconducting crystals so small that they exhibit quantum effects, resulting in size-dependent properties. This unique characteristic allows quantum dots to be tailored for specific applications, making them valuable for technologies like QLED displays and solar cells.
A quantum dot consists of an inorganic core surrounded by surface molecules. To expand engineering control over QD properties, techniques for exchanging these surface molecules are actively being developed. However, the limited understanding of QD surface chemistry hinders efficient nanomaterial design and functionalization. In this project, we compared QD systems prepared using different methods to better understand their surface chemistry and guide the development of more effective surface molecule exchange techniques.
We synthesized the material following a specific experimental procedure and then replaced its surface molecules. Then, we incrementally added either the original or new surface molecules and monitored changes using magnetic resonance spectroscopy – an analytical technique that provides insights into the structure of molecules. Additionally, we developed a MATLAB script to analyze the data more efficiently, extracting valuable quantitative details about the material.
The insights gained from this analysis helped us evaluate the effectiveness of the molecule exchange process and improve the experimental methods. Ultimately, the results of this project aim to improve molecule exchange techniques for customizing QD surfaces, paving the way for advanced material designs and broader technological applications.
Through this project, I had the opportunity to refine my computational skills and apply them to a clearly defined research problem. I also connected with graduate students and postdoctoral researchers at MIT and received valuable scientific and career advice. Additionally, I enhanced my science communication skills by presenting my work to audiences with varying levels of expertise. I am deeply grateful to my research mentors, the Praxis Independent Study course staff, and my Praxis faculty advisor for this incredible opportunity!