The high spontaneous and piezoelectric polarization in nitride semiconductors were discovered in late 1990s. The implications of polarization fields in nitride semiconductor heterostructures developed at several places including at Cornell University led to the success story of GaN HEMTs for high speed electronics and for power electronics. In 2009, it was discovered that AlScN can boast a piezoelectric coefficient that is nearly 400% higher than AlN, and in 2019 it was discovered that AlScN is ferroelectric. The nitride semiconductors therefore offer an exciting playground for studying the interaction of strong electronic polarization in semiconductors, and its many exciting device applications. At Cornell, a small and close-knit team is exploring the science and technological applications of very high polarization in semiconductors and enabling new applications in electronics, photonics, and quantum technologies.
Our papers in this area in chronological order
2022
372 APL Epitaxial ScAlN on GaN exhibits attractive high-K dielectric properties
371 APL Distributed polarization-doped GaN p-n diodes with near-unity ideality factor and avalanche breakdown voltage of 1.25 kV
364 Adv. Elect. Mat. Very high density (>1e14/cm2) polarization-induced 2D hole gases observed in undoped pseudomporphic InGaN/AlN heterostructures
363 APL Quantitative scanning microwave microscopy of 2D electron and hole gases in AlN/GaN heterostructures
2021
359 APEX Influence of collector doping setback in the quantum transport characteristics of GaN/AlN resonant tunneling diodes
358 IEEE ICSAF Towards realizing low coercive field operation of sputtered ferroelectric AlScN
357 DRC Large-signal response of AlN/GaN/AlN HEMTs at 30 GHz
355 IEEE ISAF Temperature-dependent Lowering of Coercive Field in 300 nm Sputtered Ferroelectric AlScN
353 APL Polarization-induced 2D hole gases in pserudomorphic undoped GaN/AlN heterostructures on single-crystal AlN substrates
347 SST Next-generation electronics on the ultrawide-bandgap aluminum nitride platform
345 JAP High-conductivity polarization-induced 2D hole gases in undoped GaN/AlN heterojunctions enabled by impurity blocking layers
343 APL Materials Strong effect of scandium source purity on chemical and electronic properties of epitaxial ScAlN/GaN heterostructures
337 PSSR Electric Fields and Surface Fermi Level in Undoped GaN/AlN 2D Hole Gas Heterostructures
333 JEDS First RF Power Operation of AlN/GaN/AlN HEMTs with >3 A/mm and 3.3 W/mm at 10 GHz
2020
332 IEDM GaN/AlN p-channel HFETs with Imax>420 mA/mm and ~20 GHz fT/fmax
327 Optics Express Distributed-feedback blue laser diode utilizing a tunnel junction grown by plasma-assisted molecular beam epitaxy
326 APL N-Polar GaN/AlN Resonant Tunneling Diodes
324 TED Prospects for Wide-Bandgap and Ultra-Wide-Bandgap CMOS Devices
323 TED Impact of Residual Carbon on Avalanche Voltage and Stability of Polarization-Induced Vertical GaN p-n Junction
319 APL Structural and Piezoelectric Properties of ultra-thin ScAlN Films grown on GaN by Molecular Beam Epitaxy
317 APL Light-Emitting Diodes With AlN Polarization-Induced Buried Tunnel Junctions: A Second Look
316 APL Bottom Tunnel Junction Blue Light-Emitting Field-Effect Transistors
308 PSS(a) All-Epitaxial Bulk Acoustic Wave Resonators
306 PSS(b) Oxygen Incorporation in the MBE growth of ScGaN and ScAlN
304 Phys. Rev. Applied Fighting Broken Symmetry with Doping: Towards Polar Resonant Tunneling Diodes with Symmetric Characteristics
303 APL Multiferroic LuFeO3 on GaN by MBE
302 APL Gallium nitride tunneling field-effect transistors exploiting polarization fields
299 PSS(b) MBE growth of large-area GaN/AlN 2D hole gas heterostructures
295 Optics Express Enhanced injection efficiency and light output in bottom tunnel-junction LEDs
2019
293 IEDM GaN/AlN Schottky-gate p-channel HFETs with InGaN contacts and 100 mA/mm on-current
285 TED Breakdown Walkout in Polarization-Doped Vertical GaN Diodes
284 APL MBE growth of ScN on hexagonal SiC, GaN, and AlN
283 Science A polarization-induced 2D Hole Gas in undoped Gallium Nitride Quantum Wells
282 ECS Trans. GaN-Based Multiple 2DEG Channel BRIDGE (Buried Dual Gate) HEMT Technology for High Power and Linearity
277 EDL High Breakdown Voltage in RF AlN/GaN/AlN Quantum Well HEMTs
275 APL Wurtzite phonons and the mobility of a GaN/AlN 2D hole gas
271 JAP Polarization control in nitride quantum well light emitters enabled by bottom tunnel-junctions
268 JJAP The new nitrides: layered, ferroelectric, magnetic, metallic and superconducting nitrides to boost the GaN photonics and electronics eco-system
266 Phys. Rev. Applied Broken symmetry effects due to polarization on resonant tunneling transport in double-barrier nitride heterostructures
2018
261 EDL Gate-recessed E-mode p-channel HFET with high on-current based on GaN/AlN 2D hole gas
257 DRC Realization of the First GaN Based Tunnel Field-Effect Transistor
250 APL Room temperature microwave oscillations in GaN/AlN resonant tunneling diodes with peak current densities up to 220 kA/cm2
247 TED Steep Sub-Boltzmann Switching in AlGaN/GaN Phase-FETs With ALD VO2
2017
244 Adv. Elect. Mat. Ultrawide Bandgap Semiconductors: Research Opportunities and Challenges
243 CLEO Tunnel-junction p-contact sub-250 nm deep-UV LEDs
239 DRC High-temperature p-type polarization doped AlGaN cladding for sub-250 nm deep-UV quantum well LEDs by MBE
234 Phys. Rev. X New Tunneling Features in Polar III-Nitride Resonant Tunneling Diodes
229 APL Electron mobility in polarization-doped Al0-0.2GaN with a low concentration near 1017 /cm3
224 APL Strained GaN Quantum-Well FETs on Single-Crystal Bulk AlN Substrates
2015
202 DRC Deep-UV LEDs using polarization-induced doping: Electroluminescence at cryogenic temperatures
201 DRC High-voltage polarization-induced vertical heterostructure p-n junction diodes on bulk GaN substrates
199 IEDM Steep subthreshold swing tunnel FETs: GaN/InN/GaN and transition metal dichalcogenide channels
197 APL Ferroelectric transition in compressively strained SrTiO3 thin films
196 APL Polarization-induced Zener tunnel diodes in GaN/InGaN/GaN heterojunctions
192 JXCDS Transistor Switches using Active Piezoelectric Gate Barriers
191 JXCDS Polarization-Engineered III-Nitride Heterojunction Tunnel Field-Effect Transistors
2014
180 IEDM Sub 60mV/decade Steep Transistors with Compliant Piezoelectric Gate Barriers
176 DRC GaN lateral PolarSJs: Polarization-doped super junctions
163 EDL GaN Heterostructure Barrier Diodes (HBD) exploiting Polarization-induced Delta-doping
162 APL Two-dimensional electron gases in strained quantum wells for AlN/GaN/AlN double heterostructures FETs on AlN
158 APL Tunnel-Injection Quantum Dot deep-UV LEDs with Polarization-Induced Doping in III-Nitride Heterostructures
2013
148 EDL Polarization-Induced GaN-on-Insulator E/D Mode p-Channel Heterostructure FETs
133 APL Tunnel-injection GaN quantum-dot ultraviolet light-emitting diodes
2012
126 DRC A surface-potential based compact model for GaN HEMTs incorporating polarization charges
124 DRC Ultra-thin Body GaN-on-insulator nFETs and pFETs: Towards III-nitride complementary logic
122 APL Polarization effects on gate leakage in InAlN/AlN/GaN HEMTs
117 JAP Surface potential analysis of AlN/GaN heterostructures by electrochemical capacitance-voltage measurements
108 EDL Effect of Optical Phonon Scattering on the Performance of GaN Transistors
107 EDL Ultra thin GaN-on-Insulator Quantum Well FETs with Regrown MBE Contacts Â
102 Semic. Sc. Tech. Charge transport in non-polar and semi-polar III-V nitride heterostructures
2011
93 APL Presence and origin of interface charges at atomic-layer deposited Al2O3/III-nitride heterojunctions
92 APL N-Polar III-nitride quantum well light emitting diodes with polarization-induced doping
85 APL Stark-Effect Scattering in Rough Quantum Wells
81 Phys. Stat. Sol. Subcritical Barrier AlN/GaN E/D-Mode HFETs and Inverters
79 Phys. Stat. Sol. Polarization Engineering in Group-III Nitride Heterostructures: New Opportunities for Device Design
2010
74 APL High mobility two-dimensional electron gases in nitride heterostructures with high Al composition AlGaN alloy barriers
69 APL Polarization-mediated remote surface roughness scattering in ultrathin barrier GaN high-electron mobility transistors
68 Phys. Rev. B Anisotropic charge transport in nonpolar GaN quantum wells: Polarization-induced line charge and interface roughness scattering
67 EDL Gate-recessed Enhancement-Mode InAlN/AlN/GaN HEMTs with 1.9 A/mm Drain Current Density and 800 mS/mm Transconductance
65 EDL Threshold Voltage Control in Al0.72Ga0.28N/AlN/GaN HEMTs by Work-Function Engineering
64 Phys. Stat. Sol. Short-period AlN/GaN p-type superlattices: Hole transport usage in p-n Junctions
61 APL Polarization-engineered removal of buffer leakage for GaN Transistors
60 Science Polarization Induced Hole Doping in Wide Bandgap Uniaxial Semiconductor Heterostructures
2009
59 Phys. Rev. Lett. Polarization Induced Zener Tunnel Junctions in Wide Bandgap Heterostructures
2008
47 DRC Polarization Induced Graded AlGaN pâ€n Junction grown by MBE
36 APL Very Low Sheet Resistance and Shubnikov de-Haas Oscillations in Two-Dimensional Electron Gases at Ultrathin Binary AlN/GaN Heterojunctions
2007
30 ECS Trans. MBE-grown Ultra-Shallow AlN/GaN HFET Technology
26 APL A High-Mobility Window for Two-Dimensional Electron Gases at Ultrathin AlN/GaN Heterojunctions
23 Phys. Rev. Lett. Enhancement of carrier mobility in semiconductor nanostructures by dielectric engineering
2006
22 JAP Compositional modulation and optical emission in AlGaN epitaxial films
17 APL Carrier transport and confinement in polarization-induced 3-D electron slabs: Importance of alloy scattering
16 APL Electron mobility in graded AlGaN alloys
2004
13 JAP Dipole Scattering in highly polar semiconductor alloys
12 APL AlGaN/GaN polarization-doped field-effect transistor for microwave power applications
2003
11 Phys. Rev. B Magnetotransport properties of a polarization-doped three-dimensional electron slab
9 Phys. Stat. Sol. Magnetotransport measurement of effective mass, quantum scattering time, and alloy scattering potential of polarization-doped 3D electron slabs
2002
6 APL Realization of wide electron slabs by polarization bulk doping in graded III-V nitride semiconductor alloys