Remote epitaxy for fabricating flexible and transferable devices
Young Joon Hong
Department of Nanotechnology and Advanced Materials Engineering, Graphene Research Institute, Sejong University, Seoul 05006, Korea
Current solid-state electronics are under development toward the paradigm shift from miniaturization to deformable form factor. However, typical semiconductors, including Si, III-V, metal-oxides, etc., are not intrinsically soft for fabricating the deformable devices. An innovative way to fabricate flexible electronics is to make the device overlayer away from the rigid substrate and to assemble the devices on the other soft substrate. To separate the overlayer from the mother substrate, high energy irradiation (e.g., laser lift-off) and the use of corrosive etchants had been necessary before emergence of non-covalent epitaxy (van der Waals and remote epitaxy). The remote epitaxy is to grow epitaxial overlayer remotely from wafer across a gap made of two-dimensional atomic layer. The technique has no restriction in use of poly-domain graphene, which is distinct from the van der Waals epitaxy. In this talk, we focus to present and discuss how the remote epitaxy of micro- or nano-sized epitaxial architectures is applied to fabricate deformable and transferable devices. We introduce the random nucleation-based remote epitaxy of ZnO and GaN micro-sized rod, whose spatially isolated geometry can be devised to fabricate the flexible light-emitting diodes (LEDs). We also present the white LEDs fabricated by the remote epitaxy. To increase the versatility of the remote epitaxy, it is necessary to control the position and size of rod structures. Thus, the methods of site-selective remote epitaxy are presented. The density-functional theory simulation and atomic-resolution transmission electron microscopic analysis results are also discussed.
Biography:
Dr. Hong is currently a professor at Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Korea. He received his B.S. degree in Materials Science & Engineering from Korea University in 2004, and Ph.D. from Pohang University of Science and Technology (POSTECH) in 2011. From 2011 to 2012, Dr. Hong worked as a JSPS Foreigner Research Fellow in Research Center for Integrated Quantum Electronics (RCIQE) at Hokkaido University, Japan. His research includes epitaxy of compound semiconductors on 2d material substrate and quantum-dot lighting devices for display applications.