Walter P. Murphy Professor of Materials Science and Engineering and Electrical Engineering & Computer Science (by courtesy)
Our laboratory develops thin films and nanostructures for electronic, magnetic, and photonic materials applications, with emphasis on semiconductor and ferroic oxide thin films. Metal-organic vapor phase epitaxy techniques have been developed and applied to both narrow band gap and wide band gap compound semiconductors including InMnSb, InMnAs and InGaN alloy semiconductors. Their electronic, optical and magnetic properties are characterized using a variety of techniques including photoluminescence spectroscopy, magneto-optic Kerr effect, and magnetoresistance measurements. Ferromagnetic InMnAs and InMnSb are being developed as magnetic materials for spintronics. Heterojunction spintronic devices are fabricated and their transport properties measured.
We are now developing a new class of widegap compound semiconductors for x-ray and gamma ray detection. Semiconductor photodetectors are fabricated and their opto-electronic properties determined. The defect properties are determined by photoluminescence and photo-induced current transient spectroscopy measurements.
We are synthesizing epitaxial oxides by metal-organic vapor phase epitaxy and molecular beam epitaxy for applications in nanophotonics and nanomagnetics. Emphasis is currently on the development of ferroelectric and ferromagnetics oxide epitaxial thin films and superlattices. We measure their nonlinear optical properties as well as their magnetic and magneto-electric properties. The ferroelectric domain structure is determined from electro-optical and microwave property measurements. Development of thin film photonic crystals for electro-optic modulator, laser, and optical amplifiers for opto-electronic integrated circuits (OEICs) is under way.
- Fellow, Optical Society of America, 2014
- Fellow of the American Physical Society, 2003
- Fellow, ASM, 1996
“Photonic crystal waveguide electro-optic modulator with a wide bandwidth,” with J. Li, Z. Liu, Y. Tu, S.-T. Ho, I. Jung, L.E. Ocola, and B.W. Wessels, Journal of Lightwave Technology, 31, 1601 (2013).
“Dimensional reduction: a design tool for new radiation detection materials,” John Androulakis, Sebastian C. Peter, Hao Li, B.W. Wessels, et al., Advanced Materials, 23 4163 (2011).
“Hexagonal photonic crystal waveguide based on barium titanate thin films,” with Jianheng Li, Zhifu Liu, B.W. Wessels, et al., Optical Components and Materials Viii, SPIE 7934 79340R (2011).
“Spin-dependent magnetotransport in a p-InMnSb/n-InSb magnetic semiconductor heterojunction,” with J. A. Peters, N. Rangaraju, C. Feeser and B.W. Wessels, Applied Physics Letters, 98 19 193506 (2011).
“Magnetotransport properties of InMnSb magnetic semiconductor thin films,” with J.A. Peters, N.D. Parashar, N. Rangaraju, and B.W. Wessels, Physical Review B, 82 20 205207 (2010).
“Magnetoamplification in a bipolar magnetic junction transistor,” J.A. Peters, N. Rangaraju, and B.W. Wessels, Physical Review Letters, 105 117202 (2010).