Bipasha Debnath attended the 1st Joint Polish-German Crystallographic Meeting 2020 in Wrocław/Poland. In the lighting talk session she presented her study of transport properties at the single-crystal based charge transfer interfaces and was awarded with a Presentation Award by STOE. Below she will tell us about herself and her experiences.
What fascinates you about transport properties?
Fabrication of organic solar cells (OSOL) was my first-hand experience with organic electronics. It was fascinating to see the evaporated organic semiconductor materials in the donor-acceptor pattern that turns into either an OSOL or organic light-emitting diode, depending on materials in use and process. Interestingly, these semiconductor materials behave as an insulator individually; however, in contact, they transfer charges at their interface. Of course, as a precondition, we have to make sure the ionization potential and electron affinities of donor and acceptor materials, respectively, are on the same level. Besides this only condition, the underlying mechanism of charge transfer is yet to be understood completely. These were the first interest points to make me keen to learn more about organic semiconductors. This interest made me realize that we need to study these materials individually first to tune them more effectively in organic electronics, which will eventually lead to an improved application at a commercial level.
How did you end up in your theme of work?
Most of the organic electronics are made from the film form of semiconductor materials, which makes it difficult to understand the intrinsic properties of theirs. Single crystals are one of the solutions to this problem. When I was looking for a topic for my master thesis, I learned about the organic single-crystal group in IFW Dresden, which was very new in the entire campus. Here I started to learn more about organic materials, especially small molecules, aka oligomers in crystalline form. All thanks go to my supervisors Dr. Yulia Krupskaya (group leader of the organic single-crystal group) and Professor Dr. Stefan C. B. Mannsfeld (Professor of Organic Device group). For my thesis, I first started working with charge transfer interfaces, which I am continuing now as my doctoral project.
What was the biggest difficulty you faced during your work/thesis?
We synthesize our crystals, fabricate the whole device manually, and electrically characterize them in our lab. We do everything from scratch, which is a privilege. Being a lab-rat myself, I enjoy it thoroughly. However, to do all these things, one after another with great care and precision, takes lots of time and patience. Sometimes these things are pretty exhausting. Moreover, now we are working with some exclusive, expensive materials, which take forever to receive from the manufacturer. Apart from this small thing, I feel so grateful for having the opportunity to do what I love to do.