Thursday, August 20, 2015

URSP Student Iris Stone Studies the Optical Properties of Charge Transfer (CT) Crystals

Participating in the summer URSP program through OSCAR has allowed me to continue my research with Dr. Vora, a physics professor whose research focuses on solid state physics. In my last blog post, I detailed the arduous but rewarding process of building a lab from scratch. After several months of hard work we’ve finally reached the point where we’ve been able to take real data! Our team and the types of materials we’re studying have also expanded, giving me a great opportunity to learn new science and make friends with like-minded students. 
Although I wasn’t originally sure what area of physics most interested me, my work with Dr. Vora over the past several months encouraged me to continue exploring solid state materials for my summer project. My primary goal this summer was to study the optical properties of charge transfer (CT) crystals. Unlike atomic crystals, in this case the crystal structure is formed by stacks of repeating donor and acceptor molecules. This unique arrangement gives way to emergent physics that goes beyond the individual properties of the constituent molecules. In the long run, our goal is to understand and harness these materials to achieve designer organic electronics. Organic electronics offer several advantages over traditional semiconductor technology, from lower cost of processing to compatibility with current production methods. They also offer the advantage of being lighter and thinner than traditional electronics and have great potential in flexible digital displays.

Unsurprisingly for scientists, my summer has been a lot about taking data and interpreting the results. For example, when we measure the absorption properties of CT Crystals in different stoichiometries (different ratios of acceptors and donor molecules) we see significant differences, suggesting that some ratios are conducive to co-crystallization (the stack-like arrangement) while others are not.

But the life of a lab research assistant isn’t all fun and graphs. In fact, on a daily basis I spend a lot of my time designing and optimizing our optical setups. Working with optics requires incredible precision, and even the slightest mistake in the alignment could disrupt our ability to take measurements. The really exciting moments come well after the design stage, when every aspect of the setup – the mirrors, lenses, beam splitters, rejection filters, and so on – are aligned perfectly. Only then can I fire up our spectrometer and watch the data roll in.  

The lab still sports a long to-do list, and frankly that’s the way I prefer it. I already have plans to continue my work with Dr. Vora into the fall semester, and hopefully beyond! The opportunity to work on these long-term projects and carry an idea through from start to finish has been an invaluable one. Every day I learn something new about the experimental process and the far-reaching applications of our research, offering me a glimpse into my future as a physicist.