31 citations · 66 across the 25 of their papers we have counts for
26 papers
Three-Dimensional Imaging of High-Density Dislocation Networks and Their Interactions using Multislice Electron Ptychography
Eegene Chung, Anand Ithepalli, Naomi Pieczulewski +6
Development of novel devices often involve combining functional materials and substrates, each chosen for particular physical properties such as low-loss or thermal conductivity. T…
Growth and Interface Engineering of Superconducting TiN on Sapphire by Thermal-Laser Epitaxy
Anthony Hyatt, Anand Ithepalli, Eegene Clara Chung +6
Thermal-laser epitaxy (TLE) extends the accessible pressure, temperature, and growth-rate regimes of conventional molecular-beam epitaxy, enabling in situ laser annealing, high-pur…
Fabrication-free assessment of microwave losses in germanium-based dielectrics and superconductors
Haoran Lu, Kushagra Aggarwal, Xiangqin Wang +10
We present a flip-chip-based sensing scheme to measure effective microwave losses associated with target materials for quantum technologies, without requiring any device fabricatio…
High-Q superconducting microwave resonators using MBE titanium nitride
Anand Ithepalli, Haoran Lu, Eegene Clara Chung +9
Using molecular beam epitaxy, we have realized thin films of titanium nitride (TiN) on c-plane sapphire that exhibit the lowest observed full-width at half maximum X-ray rocking cu…
Second-Order Optical Nonlinearity of AlScN Films Grown By Molecular Beam Epitaxy
Joongwon Lee, Thai-Son Nguyen, Len van Deurzen +8
Alloys of AlN have rapidly emerged as a material platform for nonlinear optics. In this paper, we measure the second-order optical nonlinearity of AlScN films grown directly on nit…
Loss Mechanisms in Cryogenic Microwave Epitaxial AlN Resonators
Hemant Gulupalli, Navnil Choudhury, Jiacheng Xie +6
Epitaxial aluminum nitride (AlN) thin-film bulk acoustic resonators (FBARs) enable low loss filtering for future 6G systems. They also provide a compact approach for qubit sensing…
Dependence of the Mn sticking coefficient on Ga-rich, N-rich, and Ga/N-flux-free conditions in GaN grown by plasma-assisted molecular beam epitaxy
YongJin Cho, Changkai Yu, Huili Grace Xing +1
This brief report examines the influence of Ga/N flux conditions on Mn incorporation in GaN. Mn-doped GaN layers were grown at 680C by molecular beam epitaxy on a Ga-pola…
Shubnikov-de Haas oscillations of two-dimensional electron gases in AlYN/GaN and AlScN/GaN heterostructures
Yu-Hsin Chen, Thai-Son Nguyen, Isabel Streicher +4
AlYN and AlScN have recently emerged as promising nitride materials that can be integrated with GaN to form two-dimensional electron gases (2DEGs) at heterojunctions. Electron tran…
Edge emission from 265~nm UV-C LEDs grown by MBE on bulk AlN
Shivali Agrawal, Hsin-Wei S. Huang, Debaditya Bhattacharya +6
UV-C LEDs pseudomorphically grown by MBE on bulk AlN substrates emitting at 265 nm are demonstrated. High current density up to 800 A/cm, 5 orders of on/off ratio, and low diff…
Low Resistance Non-Alloyed Ohmic Contacts to High Al Composition n-type AlGaN
Joseph E. Dill, Xianzhi Wei, Changkai Yu +6
Ohmic contacts to high (>70\%) Al content n-type AlGaN ultra-wide bandgap semiconductor layers in nitride electronic and photonic devices are typically fabricated by a…
Effect of substrate miscut angle on critical thickness, structural and electronic properties of MBE-grown NbN films on c-plane sapphire
Anand Ithepalli, Saumya Vashishtha, Naomi Pieczulewski +7
We report the structural and electronic properties of niobium nitride (NbN) thin films grown by molecular beam epitaxy on c-plane sapphire with miscut angles of , $2^…
A Compact Model for Polar Multiple-Channel Field Effect Transistors: A Case Study in III-V Nitride Semiconductors
Aias Asteris, Thai-Son Nguyen, Huili Grace Xing +1
A compact analytical model is developed for the mobile charge density of polar multiple channel field effect transistors. Two dimensional electron and hole gases can be potentially…
Lorentzian Switching Dynamics in HZO-based FeMEMS Synapses for Neuromorphic Weight Storage
Shubham Jadhav, Kaustav Roy, Luis Amaro +6
Neuromorphic computing demands synaptic elements that can store and update weights with high precision while being read non-destructively. Conventional ferroelectric synapses store…
Improved operating voltage in InGaN-capped AlGaN-based DUV LEDs on bulk AlN substrates
H-W S. Huang, S. Agrawal, D. Bhattacharya +2
Better wall plug efficiency of deep-ultraviolet light emitting diodes (DUV-LEDs) requires simultaneous low resistivity p-type and n-type contacts, which is a challenging problem. I…
Generalized quantum limits of electrical contact resistance and thermal boundary resistance
Alice Ho, Jashan Singhal, Deji Akinwande +2
The importance of electrical contact resistance and thermal boundary resistance has increased dramatically as devices are scaled to atomic limits. The use of a rich range of materi…
XHEMTs on Ultrawide Bandgap Single-Crystal AlN Substrates
Eungkyun Kim, Yu-Hsin Chen, Naomi Pieczulewski +4
AlN has the largest bandgap in the wurtzite III-nitride semiconductor family, making it an ideal barrier for a thin GaN channel to achieve strong carrier confinement in field-effec…
The effect of boron incorporation on leakage and wake-up in ferroelectric Al_{1-x}Sc_xN
Maike Gremmel, Chandrashekhar Prakash Savant, Debaditya Bhattacharya +3
This study explores the influence of boron incorporation on the structural and electrical properties of ferroelectric Aluminum Scandium Nitride (Al_{1-x}Sc_xN ) thin films, focusin…
Epitaxial high-K AlBN barrier GaN HEMTs
Chandrashekhar Savant, Thai-Son Nguyen, Kazuki Nomoto +8
We report a polarization-induced 2D electron gas (2DEG) at an epitaxial AlBN/GaN heterojunction grown on a SiC substrate. Using this 2DEG in a long conducting channel, we realize u…
Growth and characterization of single crystal cubic TaN and hexagonal TaN films on c-plane Sapphire
Anand Ithepalli, Amit Rohan Rajapurohita, Arjan Singh +7
Two single crystal phases of tantalum nitride were stabilized on c-plane sapphire using molecular beam epitaxy. The phases were identified to be -TaN with a rocksalt cubic struc…
Shubnikov-de Haas oscillations in coherently strained AlN/GaN/AlN quantum wells on bulk AlN substrates
Yu-Hsin Chen, Jimy Encomendero, Huili Grace Xing +1
We report the observation of Shubnikov-de Haas (SdH) oscillations in coherently strained, low-dislocation AlN/GaN/AlN quantum wells (QWs), including both undoped and -doped stru…
Quantum oscillations of holes in GaN
Chuan F. C. Chang, Joseph E. Dill, Zexuan Zhang +12
GaN has emerged to be a major semiconductor akin to silicon due to its revolutionary impacts in solid state lighting, critically enabled by p-type doping, and high-performance radi…
Two-Carrier Model-Fitting of Hall Effect in Semiconductors with Dual-Band Occupation: A Case Study in GaN Two-Dimensional Hole Gas
Joseph E. Dill, Chuan F. C. Chang, Debdeep Jena +1
We develop a two-carrier Hall effect model fitting algorithm to analyze temperature-dependent magnetotransport measurements of a high-density ( cm/Vs) polar…
Lattice-Matched Multiple Channel AlScN/GaN Heterostructures
Thai-Son Nguyen, Naomi Pieczulewsi, Chandrashekhar Savant +6
AlScN is a new wide bandgap, high-k, ferroelectric material for RF, memory, and power applications. Successful integration of high quality AlScN with GaN in epitaxial layer stacks…
In situ etching of \b{eta}-Ga2O3 using tert-butyl chloride in an MOCVD system
Cameron A. Gorsak, Henry J. Bowman, Katie R. Gann +9
In this study, we investigate in situ etching of \b{eta}-Ga2O3 in a metal-organic chemical vapor deposition (MOCVD) system using tert-Butyl chloride (TBCl). We report the successfu…