We are a semiconductors devices group. Our primary goal is to make new devices to exploit, and understand new physics. This approach leads us naturally to explore some of the fundamental limits of semiconductor devices. In recent years, we are immersed in research on the following topics (with Prof. Xing’s group):
- the performance limits of ultrahigh speed GaN transistors,
- wide bandgap semiconductor transistors for power electronics (see Energy.gov presentation),
- all-electronic THz sources,
- ultra-low power sub-Boltzmann switching transistors by tunneling and other mechanisms,
- deep-UV LEDs and lasers approaching 200 nm using quantum dots, and
- extreme-electron concentration devices in oxides.
Often this research path requires us to explore new materials. We grow the new materials by ourselves using Molecular Beam Epitaxy (MBE), or work very closely with groups that do. The goal to make devices also requires, or results in, a deep theoretical understanding of electron transport, electron-phonon interactions, light-matter interactions, geometric and topological aspects of condensed matter physics, and correlated electron physics. We do a significant amount of theory and modeling ourselves, and work closely with theoreticians when things get out of our reach.
Molecular Beam Epitaxy (MBE): for the growth of quantum structures
Structural Characterization: X-Ray Diffraction, AFM, SEM, TEM
Electronic Characterization: Hall effect, Magnetotransport, I-V, C-V, Hi-Frequency RF
Optical Characterization: Absorption spectroscopy, Photoluminescence, Electroluminescence
Device Design: Analytical modeling, Transport theory, Energy-Band diagram based design, TCAD modeling
Device Fabrication: Lithography (Optical & Electron Beam), Etching (wet & dry), Metal deposition, ALD dielectrics
Device Testing: Transistor characteristics over a large range of frequencies and voltages, and LEDs over a large range of wavelengths
III-Nitrides: GaN, AlN, InN, BN, their alloys and heterostructures
2D Crystals: Graphene, MoS2, Transition metal dichalcogenides (TMDs)
Oxide Family: Complex oxides (STO/GTO heterostructures), and Extreme-Bandgap Oxides (Ga2O3)
Here are our research publications.
I found this on the web: A small reminder to anyone who spends too much time thinking about semiconductors. (Note that this is a LINK to someone else’s page!).
Department of Electrical Engineering
(djena [at] nd [dot] edu)