Chemical Engineering Professor Christos Dimitrakopoulos was part of a research team whose paper, entitled “Principle of direct van der Waals epitaxy of single-crystalline films on epitaxial graphene,” was published on September 11 in the high-impact journal Nature Communications. Nature Communications is a multidisciplinary journal that publishes high-quality research from all areas of the natural sciences and has an Impact Factor of 10.742 according to the 2013 Journal Citation Reports® Science Edition (Thomson Reuters, 2014). Papers published by the journal represent important advances of significance to specialists within each field.

The authors are Jeehwan Kim, Can Bayram, Hongsik Park, Cheng-Wei Cheng, Dimitrakopoulos, John A. Ott, Kathleen B. Reuter, Stephen W. Bedell, and Devendra K. Sadana.

As the abstract of the article explains: “There are numerous studies on the growth of planar films on sp2-bonded two-dimensional (2D) layered materials. However, it has been challenging to grow single-crystalline films on 2D materials due to the extremely low surface energy. Recently, buffer-assisted growth of crystalline films on 2D layered materials has been introduced, but the crystalline quality is not comparable with the films grown on sp3-bonded three-dimensional materials. Here we demonstrate direct van der Waals epitaxy of high-quality single-crystalline ​GaN films on epitaxial graphene with low defectivity and surface roughness comparable with that grown on conventional ​SiC or sapphire substrates. The ​GaN film is released and transferred onto arbitrary substrates. The post-released graphene/​SiC substrate is reused for multiple growth and transfer cycles of ​GaN films. We demonstrate fully functional blue light-emitting diodes (LEDs) by growing LED stacks on reused graphene/​SiC substrates followed by transfer onto plastic tapes.” (September 2014)