March 31, 2010
Dr. Chris Summers
Professor of Materials Science and Engineering and
Director of the Phosphor Technology Center of Excellence
“Application of Atomic Layer Deposition for the Fabrication of Photonic Crystals and Bio-derived Structures”
Abstract: We review the application of atomic layer deposition (ALD) coupled with selective etching protocols to fabricate photonic crystals (PCs) and to investigate/emulate bio-derived structures. ALD uniquely complements a number of template technologies by providing a mechanism to invert, replicate and convert materials while precisely retaining the form of the original template. By this process additional functionalities can be added and the processing range significantly enhanced, for example, when high melting point materials are substituted for low melting point materials. Additionally, sacrificial layer and conformal backfilling techniques enable the refinement of lattice geometries and thereby, tuning of the optical properties. This is demonstrated for synthetic silica opals, holographically formed polymer templates and bio-derived templates; where dielectric lattice inversion, and the development of large pore structures offer significant enhancement to the photonic band gap by backfilling with different high-index materials.
Recently we have investigated the ALD technique for the fabrication of novel devices, such as the annular PC, which has a high index pillar at the center of each hole and which is theoretically predicted to exhibit a photonic band gap at the same energy for both TE and TM modes. Currently we are applying ALD to emulate the properties of bio-structures and to fabricate bio-inspired devices.
Christopher J. Summers Bibliography
Professor Christopher J. Summers received his B.S.(Hons) and Ph.D. in Physics from Reading University in the UK. He has held positions at Bell Labs, GTE Labs, and McDonnell Douglas Research Labs. Following McDonnell Douglas, he joined the Georgia Tech Research Institute in 1981 and in 1993 became Director of the Phosphor Technology Center of Excellence. He is currently a professor in the Georgia Tech School of Materials Science and Engineering and an adjunct faculty member in the schools of Physics and Electrical and Computer Engineering. He has a research history in electro-optical materials characterization, the molecular beam epitaxy of infrared and electronic materials and the synthesis of phosphor materials for flat panel displays and solid state lighting. His current research interests are in propagation through 2D photonic crystals, such as self-collimation phenomena, giant refraction and superprism effects, and the use of 3D photonic crystals infiltrated by atomic layer deposition for studying luminescence modification and tunability. Recently he has applied the atomic layer deposition technique to an investigation of the optical properties of biological structures and the development of bioinspired devices. He has received numerous awards and honors, holds ten patents, and has over 300 publications.