Researchers at the IBM T. J. Watson Research Center (Yorktown Heights, NY) have figured out how to use graphene as a template to repeatedly grow and exfoliate entire single-crystalline gallium nitride (GaN) films; the process extends to the creation of GaN-based multi-quantum-well structures that can be (and have been) used to make fully functional LEDs.1
Reusable graphene template
The graphene, which is epitaxially grown on a silicon carbide substrate, serves as a reusable template for growing III-nitride films. The resulting GaN-based multi-quantum-well structures are quite flexible -- flexible enough, in fact, that the blue-emitting LEDs that researchers fabricated were actually flexible LEDs transferred to plastic tape.
Such exfoliated film heterostructures can be transfered to other types of substrates as well, including silicon; as a result, the technique could become part of the device design and fabrication process for advanced silicon photonics devices.
1. Jeehwan Kim et al., Nature Communications (2014); doi: 10.1038/ncomms5836