In a new article published in Advanced Functional Materials (http://dx.doi.org/10.1002/adfm.201502412), Princeton Ph.D. candidate Geoff Purdum in Lynn Loo’s group in the Chemical and Biological Engineering Department at Princeton and his co-authors shed new light on this issue. In particular, they report reversible access of two polymorphs exhibited by core-chlorinated naphthalene tetracarboxylic diimide (NTCDI-1), an organic semiconductor developed by BASF. Detailed studies reveal that although the monoclinic polymorph of this compound exhibits superior electronic properties as a single crystal, nevertheless when produced as thin films, it is the triclinic phase that exhibits better charge transport properties. Careful structural studies, including in-situ GIWAXS performed at the G1 station at CHESS, suggest that in-plane charge transport anisotropy is more important than the polymorphic packing motif in this case, which may provide important guidance for future work in this ever-evolving field.
