Graduate STEM Fellow Profile

Tiffany C Kwong

Project Title: IMPACT LA: Improving Minority Partnerships and Access through CISE-related Teaching
Thesis: Optical Properties of Quantum Dot Photoluminescence
College/University: California State University, Los Angeles
Research Advisor: Dr. William Taylor
Degree Sought: Masters in Physics
Department: Physics and Astronomy Department
Research Focus: Experimental Condensed Matter Physics; Photoluminescence of Silicon doped Quantum Dots on InGaAs Substrate.
Teaching Partner(s): Brianna Rojas

Description of Research

A quantum dot a small impurity that is grown on a substrate on the order of 1500 nm in diameter. When a laser hits a quantum dot doped semiconductor, the light irradiates the electrons and excite them to higher quantized energy levels, which then cascade back to lower energy levels (photoluminescence). On earth, our atmosphere protects us from strong radiation, the effects of such radiation on quantum dot doped semiconductors are unknown, and it is our goal to measure the degradation of the photoluminescence of the quantum dots by simulating these harsh conditions by bombarding the sample with 1 MeV protons.

Example of how my research is integrated into my GK-12 experience

When the students were learning about the number line, we used a thermometer to show thermal expansion. The students acted as atoms in a substance at different temperatures to show the effects temperature has on the volume of the liquid in the thermometer and atomic movement. Using this new found knowledge that atoms at higher temperatures move around and collide a lot in the substance while atoms at freezing temperatures are pretty much stagnant, they were able to explain, why when shooting a laser at the quantum dots, we cool the system with liquid nitrogen. Not only did they understand a component of my research, they realized that this is pertinent in biology, chemistry, and forensics they have seen on television.