Wunderbar Deutschland (Wonderful Germany) - Week 6

Week 6: Simple yet complex

by Pin-Wen Wang

I think that out of everything I’ve learned, the concept of photoluminescence is probably the single most important fundamental (but not complex) concept that I needed to understand to help me with my research. When you break up the word photoluminescence, it’s just “photo” and “luminescence”. Luminescence is the phenomenon of a material giving off light. “Photo” refers to photons or packets of energy that, in physics, quantifies the energy that creates light. What photoluminescence of a material refers to, then, is a material’s ability to give off light by giving off these packets of energy.

A very similar concept is bioluminescence, which can be likened to the way a firefly gives off light, by biological/chemical processes within its body. For my research, I needed to count how many photons were given off by “my” nanoparticle materials when I agitate the material with a laser, giving the material energy. The number of photons that are given off though isn’t constant, nor does it follow a well defined curve. That’s where my research comes in.

When I was charged with the task of characterizing nanoparticles, I struggled to understand why I was doing it. I didn’t know what type of experiments to design because I didn’t know what I wanted to see, simply because I didn’t know. We didn’t know how the nanoparticles would react or what they would do. I understood photoluminescence, but I didn’t understand the point of my research. Many times when I ask my supervisor questions about what I should be doing, he answers “if I knew the answers, we wouldn’t be doing the research”.

Through doing my research, I finally understand a whole new perspective of scientific research. It’s not really about understanding a complex concept that you only read about in textbooks. Textbooks provide you with stories, histories of what
past researchers have concluded. With my nanoparticles, learning how to use the apparatus and coding programs was not difficult. The most difficult part was trying to understand the graphs I was getting and explaining why these graphs behaved the way they do, and knowing some background information about the properties of metals and ways electrons behave in different materials. Understanding what photoluminescence is was a great jumping off point to start the journey of trying to understand something like nanoparticles.

---

About the Blogger

Pin-Wen Wang is majoring in Electrical Engineering and Computer Science at Harvard (class of 2014). This summer Pin-WenPin-Wen will be studying light’s affect/effect on Nanoparticles at the University of Duisburg-Essen in Germany. When she's not trying to figure out why  there are so many e's in "engineer", Pin-Wen likes to play frisbee, cook, and  try new foods from all over the world. Her favorite color is orange, and it's  unlikely you'll forget that when you see her walking across Harvard Yard in the  winter with her bright orange puffer jacket.