MoTe2 possesses two polymorphs: semiconducting (2H) and semi-metallic (1T') phases, separated by a small energy barrier. The 1T' phase of MoTe2 provides an excellent platform for forming low-resistance contacts with the 2H phase, where the low density of states in the semimetal suppresses metal-induced gap states (MIGS) and reduces Fermi-level pinning. However, existing fabrication methods encounter significant challenges in location control, contact quality, and device scaling. In this work, a new method is developed to synthesize 1T'-2H heterophase structures using chemical vapor deposition (CVD). By depositing pre-patterned molybdenum, seamless in-plane 1T'-2H MoTe2 heterophase junctions are synthesized in a single-step process, achieving precise control over the location of each phase and uniform MoTe2 coverage across centimeter-scale surfaces. Field-effect transistors incorporating 1T' MoTe2 contacts and 2H MoTe2 channels show p-type dominant transfer characteristics and exceptionally low contact resistance. The unique attributes of these 1T' MoTe2 contacts, including pristine interfaces, reduced Schottky barrier heights, and seamless edge contacts, combined with the pronounced ambipolarity of the grown 2H MoTe2, demonstrate the commercial viability of this process for 2D transistors, addressing the long-standing challenge of contact resistance in 2D transistor technology.

Nonvolatile flip-flops and latches have been proposed as key building blocks for improving the reliability and energy efficiency of computing systems operating under aggressive power gating and intermittent power availability. Ferroelectric field-effect transistors (FeFETs) based on van der Waals (vdW) heterostructures provide a promising approach for nonvolatile sequential logic by enabling direct integration of memory functionality into logic devices while minimizing interface-related degradation. In this work, CuInP2S6-based vdW FeFETs are fabricated in both metal-ferroelectric-metal-insulator-semiconductor and metal-ferroelectric-semiconductor configurations, exhibiting robust ferroelectric switching and stable nonvolatile behavior. Building on these devices, ferroelectric nonvolatile inverters are realized, followed by a nonvolatile ferroelectric latch that reliably restores its logic state after complete power loss. The proposed latch leverages ambipolar MoTe2 channels to inherently drive the FeFET gate-source and gate-drain voltages to full rail-to-rail values (VGS = VGD = ±VDD) in a state-dependent manner, thereby ensuring reliable polarization switching without auxiliary sensing circuitry or additional bias-management schemes. Owing to the clean vdW interfaces and intrinsic circuit operation, the latch restores its state upon power recovery using only simple control signals. These results demonstrate the strong performance of 2D vdW FeFETs and establish nonvolatile latch operation as a viable experimental platform for nonvolatile sequential logic and energy-efficient computing architectures.

This work presents a comprehensive benchmarking of ternary content-addressable memory (TCAM) implementations using timing-accurate SPICE simulations, systematically comparing conventional CMOS designs with emerging device technologies, including magnetic tunnel junctions (MTJs), ferroelectric tunnel junctions (FTJs), ferroelectric field-effect transistors (FeFETs), and 2-D reconfigurable field-effect transistors (2D RFETs). Key performance metrics, including search delay, search energy, static power, cell area, sense margin, power-supply sensitivity, and CMOS compatibility, are evaluated alongside technology-specific tradeoffs that govern scalability and robustness. The results identify FeFET-based TCAMs as the most balanced and scalable solution, delivering substantial improvements in energy efficiency, search latency, and cell area relative to CMOS baselines. 2D RFET-based TCAMs exhibit advantages in search energy, static power, and footprint; however, these benefits are offset by excessive search latency and limited CMOS compatibility, primarily stemming from material quality and process integration challenges. MTJ- and FTJ-based resistive TCAMs offer moderate gains in area and delay while maintaining strong CMOS compatibility, but suffer from prohibitively high search energy due to static power dissipation in sense amplifiers (SAs) during search operations. This behavior exposes an inherent tradeoff between energy efficiency and robustness in resistive TCAM architectures.

We demonstrate high-temperature operation of Al0.83In0.17N/GaN high-electron-mobility transistors (HEMTs) at 800 K (∼527 °C) enabled by a post-fabrication supercritical fluid (SCF) treatment. NH3-based SCF (NH3-SCF) and O2-based SCF (O2-SCF) processes are systematically compared, showing that O2-SCF provides more effective oxidative passivation for interface engineering under extreme-temperature conditions. The O2-SCF treatment suppresses off-state leakage current by more than five orders of magnitude at room temperature and over two orders at 800 K, while increasing on-current by 30%–40% and reducing on-resistance from 10 to 8 Ω mm. The O2-SCF devices exhibit a subthreshold swing of 64 mV/dec and an on/off current ratio of 1012 at room temperature, retaining 230 mV/dec and 104 at 800 K, among the best reported for III-nitride HEMTs operating above 500 °C. These results demonstrate that O2-SCF is an effective post-fabrication strategy for improving interface quality and mitigating performance degradation at elevated temperatures in Al0.83In0.17N/GaN HEMTs, with potential for electronics in harsh environments.

We investigate magnetotransport in a van der Waals heterostructure composed of monolayer graphene and the insulating helical antiferromagnet NiI$_2$. While NiI$_2$ is highly resistive and thus poorly suited for direct transport measurements, we demonstrate that magnetotransport in an adjacent graphene layer provides an electrical readout of magnetic-state-dependent interfacial behavior. Most notably, first-harmonic longitudinal magnetoresistance under in-plane magnetic fields exhibits large, anisotropic low-field peaks that are absent from a monolayer graphene/h-BN control device and are suppressed above the multiferroic transition temperature of NiI$_2$. Temperature-dependent harmonic measurements provide complementary evidence: the second-harmonic resistance shows the clearest nonlinear contrast relative to the control device, while the third harmonic contains a larger generic nonlinear and thermal background that is nevertheless modified in the heterostructure. These results demonstrate that graphene-based transport measurements offer a sensitive, non-invasive probe of magnetic phase behavior in electrically insulating van der Waals magnets, opening routes toward spintronic devices based on insulating vdW multiferroics.

The development of high-performance, stable and platinum-free electrocatalysts for hydrogen oxidation reaction (HOR) in alkaline media is crucial for anion exchange membrane fuel cells. Herein, a Ru-anchored WOxP composite material was designed and successfully synthesized. Compared with other traditional metal oxides, Pdoped WOx with abundant oxygen vacancies can provide adsorption sites for hydroxyl groups. The electron transfer from Ru to WOx species leads to the weakening of the hydrogen binding energy (HBE) of Ru. Oxygen defects on the support and the electron transfer regulate the adsorption of H* and OH* on the Ru and W sites, respectively. This synergistically accelerates the HOR kinetics and results in excellent HOR activity in alkaline media. Electrochemical tests show that under an overpotential of 50 mV, the optimized Ru-WOxP composite material exhibits the area-normalized exchange current density j0,s value of 347.0 mu A cmRu-2, which is 9.3 times of commercial Pt/C catalyst. This work highlights the potential of heteroatom-doped oxide supports for tuning Ru electronic structure and advancing optimized electrocatalysis for HOR.

The bridge inter-level coupling strength dependence of the electron transfer in multiple peptide-bridges mediated donor-acceptor complexes via the superexchange mechanism is examined through the quasi-adiabatic propagator path integral algorithm in this work. It is proven that the superexchange mechanism of electron transfer in the these complexes could be maintained by adjusting the inter-bridge coupling strength when the bridge-site number increased from two to six. Especially, keeping the same bridge energy as DB1A and DB2A, when the bridge inter-level coupling in DB3A or DB4A complexes is enhanced, the energy diffusion inside them is only affected, as a result of which the dephasing rates show a tendency to decrease gradually and tends to level off, meanwhile the relaxation rates climb up gradually and attain a maximum value. Therefore, in multi-peptide-bridge complexes, it could regulate the inter-bridge coupling in DBnA system to maintain the superexchange mechanism and accelerate the electron transfer rates.

The sluggish kinetics of the hydrogen oxidation reaction under alkaline conditions significantly impedes the performance of anion exchange membrane fuel cells (AEMFCs). Here, we present a new Cl- etching-induced strategy to synthesize a Ru-Ni/NiO@C composite catalyst for alkaline hydrogen oxidation. The catalyst was prepared through a two-step protocol: a solvothermal/calcination synthesis of porous Ni/NiO@C support, and the loading of Ru, where Cl- promotes localized corrosion and enhances the in situ replacement of Ni by Ru3+, generating a series of Ru-Ni/NiO@C products that show porous spherical-like structure. Electrochemical measurements demonstrated that the optimized catalyst exhibits exceptional catalytic activity for HOR in alkaline media, with a high exchange current density surpassing that of commercial Pt/C. The proposed route shows a fine tuning of the reaction condition is also useful for designing effective HOR catalysts that possess superior performance compared to noble metal based systems.

Introduction Two-dimensional (2D) materials have garnered significant attention for their exceptional physical properties and atomic-scale thickness, offering unprecedented opportunities to explore new physics and to enable next-generation electronic, photonic, and quantum devices. Despite this promise, synthesizing large-scale and high-quality 2D materials remains a major challenge, limiting their practical implementation and fundamental studies. In addition, the discovery and development of new materials, particularly those exhibiting ferroelectricity and magnetism, are crucial for revealing new phenomena and enhancing the functionalities of nanoscale devices. In this talk, I will present our group’s research on the synthesis of 2D materials and the exploration of their applications in electronic and photonic devices. Nanoscale Devices Based on Tungsten Selenium Tellurides The bandgap of ternary alloy WSe 2−2x Te 2x offers a widely tunable bandgap, covering a broad range of the electromagnetic spectrum from the infrared to visible light. However, synthesizing WSe 2−2x Te 2x alloy is very challenging due to the low chemical activity of tellurium and poor thermal stability of tellurium-based alloy. We developed a novel rapid-cooling process and successfully synthesized a variety of telluride structures, including WSe 2−2x Te 2x with spatially graded composition, core-shell structures, and lateral superlattices. 1-3 Using the WSe 2−2x Te 2x core-shell structures, we demonstrated heterogeneous transistors, which exhibit unidirectional conduction and a strong photovoltaic effect. 1 Additionally, we synthesized monolayer WSe 2−2x Te 2x /WSe 2−2y Te 2y (x > y) multi-heterostructures and WSe 2−2x Te 2x with lateral graded compositions. In the multi-heterostructures, the bandgap alternates between high and low in concentric rings, while in graded WSe 2−2x Te 2x , the bandgap changes continuously from center to edge within a monolayer flake. 2, 3 Pseudo-1D-channel photodetectors based on multi-heterostructures exhibit significantly enhanced photosensitivity. 2 These ternary tellurides with spatially modulated compositions provide a new platform for novel electronic and photonic devices with potential applications in broadband light sensing, highly sensitive imaging, and ultrafast optoelectronic integrated circuits. Large-scale Synthesis of Molybdenum Tellurides Molybdenum telluride ( MoTe 2 ) has multiple crystalline phases, including the semiconducting 2H phase and the semimetallic 1T' phase. The low phase-transition energy between these phases enables potential applications in phase-change memories. Furthermore, 1T' MoTe 2 exhibits strong spin-orbit coupling, making it a promising material for spintronic devices. We developed wafer-scale synthesis of MoTe 2 using metal-organic chemical vapor deposition (MOCVD). We found that the polymorphic phase of MoTe 2 can be controlled by tuning the growth temperature and precursor ratios. Notably, the 1T’ phase of MoTe 2 can be synthesized at 400 °C, which is compatible with silicon back-end-of-line (BEOL) processes. Furthermore, we developed the synthesis of heterophase MoTe 2 , consisting of 2H and 1T’ phase homojunctions using pre-patterned Mo precursors. 4 These 2H–1T phase heterojunctions provide an intriguing platform for high-performance logic transistors and photodetectors. Exploring 2D Ferroelectric Materials 2D ferroelectrics have emerged in recent years as a new class of ferroelectric materials, possessing many intriguing traits and significant application potential in nanoelectronics and optoelectronics. Many 2D ferroelectrics can retain ferroelectricity even down to a single unit-cell thickness and can be grown or transferred onto any substrate, enabling seamless integration with other layered materials into ferroelectric heterostructures and superlattices. We have studied various 2D ferroelectric materials including In 2 Se 3 and CuInP 2 S 6 . 5, 6 We found that the polarization in In 2 Se 3 can be modulated by both electric pulses and optical stimuli due to its semiconducting nature. 5 Utilizing these unique properties of In 2 Se 3 , we demonstrated multifunctional devices, which can concurrently serve as an electronic memory, photonic memory, logic gate, and photodetector. 5 In addition, we found that the polarization in CuInP 2 S 6 exhibits strong temperature and frequency dependence, as shown in Fig. 3b. 6 Using CuInP 2 S 6 , we demonstrated various electronic devices, including reconfigurable logic transistors, 7 content-addressable memories, 8 and ferroelectric diodes. 6 Acknowledgement The authors would like to thank the support from Entegris Incorporated under grant No. Entegris 108252 and University of Illinois at Urbana-Champaign under Research Support Award RB25042. References: (1) Xu, K.; Sharma, A.; Kang, J.; Hu, X.; et al. Adv Mater 2020, 32 (47), e2002548. (2) Hao, Z.; Xu, K.; Kang, J.; Chen, C.; et al. Nanoscale 2021, 13 (46), 19587-19592. (3) Xu, K.; Hao, Z.; Alsalman, H.; Kang, J.; et al. Appl Phys Lett 2022, 120 (23), 231903. (4) Lin, Y.; Lee, H.; Kang, J.; Wang, Z.; et al. Device Research Conference (DRC), 2025. (5) Xu, K.; Jiang, W.; Gao, X.; Zhao, Z.; et al. Nanoscale 2020, 12 (46), 23488-23496. (6) Zhao, Z.; Xu, K.; Ryu, H.; Zhu, W., ACS Appl Mater Interfaces 2020, 12 (46), 51820-51826. (7) Zhao, Z.; Rakheja, S.; Zhu, W. Nano Lett 2021, 21 (21), 9318-9324. (8) Zhao, Z.; Kang, J.; Tunga, A.; Ryu, H.; et al. Acs Nano 2024, 18 (4), 2763-2771.

The stability of anodic electrocatalyst is the bottleneck of acidic water splitting. The substitution of oxygen evolution reaction (OER) with methanol oxidation reaction (MOR) can effectively avoid this problem due to its lower theoretical voltage. In this work, we have reported the synthesis of FeCoNiCuIrPtRu high-entropy alloy nanoparticles coated by nitrogen doped carbon nanotubes (FeCoNiCuIrPtRu/NCNT) as an exceptional electrocatalyst for hydrogen evolution and methanol oxidation reaction (HER/MOR). The overpotential at 100 mA/cm2 for FeCoNiCuIrPtRu/NCNT is decreased by 72 mV by comparison with benchmark Pt/C; thus, the mass activity at-0.05 V vs. RHE was boosted by 7.2 folds. Additionally, the MOR mass activity of FeCoNiCuIrPtRu/NCNT is enhanced by a factor of 18 and 7 than PtRu/C and Pt/C, respectively. Furthermore, the NCNT confinement contributes to an excellent structural stability, suppressing the dissolution of Ru atoms contributing to a stable CO tolerance; thereby, a stable MOR catalytic activity is achieved.

Van der Waals (vdW) magnetic materials have attracted considerable attention for use in spintronic devices such as those controlled by spin-orbit torque (SOT). Such SOT-driven devices are typically fabricated by bringing a vdW magnet in proximity to a spin-charge conversion layer to achieve current-driven magnetization switching. Here, we show that such structures fabricated with iron germanium telluride (FGT) and platinum can exhibit emergent magnetic properties, which we attribute to magnetic proximity effects at the FGT/Pt interface. These changes manifest as increased perpendicular magnetic anisotropy and the emergence of additional magnetization reversal steps as probed by magneto-transport, with the most significant changes appearing in thinner flakes. The behavior was found to be robust and consistently appeared in samples made with crystals from different vendors. Our results demonstrate the potential for engineering vdW spintronic systems through magnetic proximity effects.

Emerging applications in data-intensive computing and circuit security demand logic circuits with high functional density, reconfigurability, and energy efficiency. Here, we demonstrate nonvolatile reconfigurable four-mode field-effect transistors (NVR4M-FETs) based on two-dimensional (2D) MoTe2 and CuInP2S6 (CIPS), offering both polarity switching and threshold voltage modulation. The device exploits the ferroelectric polarization of CIPS at the source/drain regions to achieve dynamic control over the transistor polarity, enabling transitions between n-type and p-type states through polarization-induced local electrostatic doping. Additionally, multilayer graphene floating gates are incorporated to modulate the threshold voltage, yielding four distinct nonvolatile operating modes: n-type logic, p-type logic, always-on memory, and always-off memory. Leveraging the four-mode property, the NVR4M-FET can function as a one-transistor-per-bit ternary content-addressable memory (TCAM). In addition, we demonstrate the construction of transformable logic gates with 14 distinct logic functions using two NVR4M-FETs and a reconfigurable half a dder/subtractor using three NVR4M-FETs integrated with load resistors. Furthermore, we show that a 2-input look-up table can be achieved with eight NVR4M-FETs compared to 12 transistors using reconfigurable transistors, highlighting the potential of NVR4M-FETs for high-density logic circuits. These results underscore the potential of NVR4M-FETs as essential building blocks for energy-efficient, in-memory computing, and secure hardware applications.

In this work, sodium dodecyl sulfate (SDS), hexadecyltrimethylammonium bromide (CTAB), g-C3N4 and graphene oxide (GO) were used to mediate the formation of Ag3PO4 crystal in order to explore the additives affecting on its structure, morphology, and photocatalytic activity. The photo catalytic properties of the obtained products were evaluated by the simulating pollutant of methylene blue (MB) solution. The morphologies, structures, and crystal forms of the prepared samples were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD), respectively. The results suggested that SDS and GO were inclined to induce the formation of the Ag3PO4 particles with polyhedral morphology which showed enhanced photo-catalytic performance. The rate constant value of Ag3PO4 which induced by SDS were 0.0407 min-1 and higher than that of CTAB. Attributed to the synergistic effect of Ag3PO4, g-C3N4 and GO, Ag3PO4/g-C3N4/GO declared the highest degradation efficiency (85 %) and rate constant (0.0426 min-1). In conclusion, the mentioned preparation of Ag3PO4-based photo-catalyst provided a new idea for using photo-catalytic technology to treat wastewater.

The scalable synthesis of materials with strong spin orbit coupling (SOC) is crucial for the development of spintronic and magnetic devices. Here, wafer-scale growth of 1T' MoTe2 using metal-organic chemical vapor deposition (MOCVD) at low temperatures (400 °C) is demonstrated. The synthesized films exhibit uniform coverage across the entire substrate, as well as accurate stoichiometry. This low-temperature synthesis is compatible with silicon back-end-of-line (BEOL) processes, enabling in-memory and in-sensor computing for data-intensive applications. Furthermore, it was found that the grown 1T' MoTe2 exhibits strong spin-orbit coupling, as revealed by the spin torque ferromagnetic resonance (ST-FMR) measurements conducted on a 1T' MoTe2/permalloy bilayer. These measurements indicate significant damping-like torques in the wafer-scale 1T' MoTe2 film and indicate high spin-charge conversion efficiency. The BEOL-compatible process and potent spin orbit torque demonstrate the promise of MOCVD-grown MoTe2 in advanced device applications.

Breakthroughs in nanotechnology have enabled the large-scale fabrication of nanoparticles with varied compositions and structures. Yet, evaluating their electrical conductivities remains challenging due to high volume and individual variability. We report a rapid, non-contact, and parallel method to characterize longitudinal nanostructures, including insulators, semiconductors, and conducting metal oxides by using MoO3, MoS2/MoO2, and MoS2 nanoribbons, produced at different fabrication stages, as a model system. Leveraging our semi-quantitative model based on Maxwell-Wagner and electrical double-layer polarization, electric conductivities of various nanoparticles are determined from their distinct electro-rotation behaviors in water, spanning six orders of magnitude. The results agree well with standard four-probe measurements. The technique, measuring multiple nanoparticles at once, without the use of electrical contact, can be easily scaled up for parallel determination of particles electric conductivities. These findings highlight a non-destructive, rapid, and simple characterization method promising to bring nanomaterials closer to practical applications in electronics, optics, sensing, catalysis, and robotics.

As a promising alternative to the Von Neumann architecture, in-memory computing holds the promise of delivering high computing capacity while consuming low power. Content addressable memory (CAM) can implement pattern matching and distance measurement in memory with massive parallelism, making them highly desirable for data-intensive applications. In this paper, we propose and demonstrate a novel 1-transistor-per-bit CAM based on the ferroelectric reconfigurable transistor. By exploiting the switchable polarity of the ferroelectric reconfigurable transistor, XOR/XNOR-like matching operation in CAM can be realized in a single transistor. By eliminating the need for the complementary circuit, these non-volatile CAMs based on reconfigurable transistors can offer a significant improvement in area and energy efficiency compared to conventional CAMs. NAND- and NOR-arrays of CAMs are also demonstrated, which enable multi-bit matching in a single reading operation. In addition, the NOR array of CAM cells effectively measures the Hamming distance between the input query and stored entries. Furthermore, utilizing the switchable polarity of these ferroelectric Schottky barrier transistors, we demonstrate reconfigurable logic gates with NAND/NOR dual functions, whose input-output mapping can be transformed in real-time without changing the layout. These reconfigurable circuits will serve as important building blocks for high-density data-stream processors and reconfigurable Application-Specific Integrated Circuits (r-ASICs). The CAMs and transformable logic gates based on ferroelectric reconfigurable transistors will have broad applications in data-intensive applications from image processing to machine learning and artificial intelligence.

Electronic dynamics of Donor-Bridge-Acceptor system with a bridge impurity incorporated in dissipative environments is studied taking advantage of the quasi-adiabatic propagator path integral approach in this article. An impurity site is introduced in the center of bridge chain of the system. The numerical calculations indicate the electron transfer rates of the system are changed when the energy gap between the center site (impurity site) and other bridge sites increased from -2.5 to 2.5 eV, the relaxation rates decrease and the dephasing rates increase as the energy gap increases, respectively under the same environment factors (e.g. temperature and system-environment coupling). However, the electron transfer mechanism of the system is hardly affected when the bridge impurity energy is increased in the range of +/- 21% relative to the other bridge energy, and the occupation populations of bridge chain are not more than 10%, which means the superexchange mechanism also works well within the context of this study.

Content-addressable memory (CAM) compares input search data with stored data, returning the address upon a match. CAMs offer high-speed parallel search, making them ideal for associative memory applications. CAMs are categorized into binary (BCAMs) and ternary CAMs (TCAMs). BCAMs store two states and require an exact match for a successful search, while TCAMs can store a third state, “don’t care” or “X”, always resulting in a match. Traditionally, CAMs are implemented using CMOS static random-access memory (SRAM). However, SRAM-based CAMs use ≥ 9 transistors, increasing the area and power dissipation. Recently, 2D reconfigurable transistors (RFETs) have emerged as a promising technology for TCAMs. 2D-RFET TCAMs offer high on/off ratio, low power consumption, non-volatile data storage, and low area requirement, using only 1T for realizing a CAM [1] .

High temperature (HT) electronics applica-tions will require the development of a broad range ofdevices made using different materials. Among thesedevices, high-electron mobility transistors (HEMTs) madewith GaN and its alloys are attractive for high-power radiofrequency (RF) applications. In this manuscript, we testedAlGaN/GaN HEMT devices having similar to 140-nm gate length atdifferent temperatures up to 500 degrees C. Devices were fab-ricated using Air Force Research Laboratory's (AFRL's)140-nmT-gate process technology. The performancedegradation measured in different devices was analyzed byconsidering changes in different device parameters and byusing appropriate device physics. Cross-sectional materi-als characterization using scanning transmission electronmicroscopy (STEM) and electron energy loss spectroscopy(EELS) was performed to understand the origin of perfor-mance degradation. This understanding will allow us todesign a sub-mu m GaN-based process technology compat-ible with HT RF applications

High temperature (HT) electronics applications will require the development of a broad range of devices made using different materials. Among these devices, high-electron mobility transistors (HEMTs) made with GaN and its alloys are attractive for high-power radio frequency (RF) applications. In this manuscript, we tested AlGaN/GaN HEMT devices having <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 140-nm gate length at different temperatures up to 500 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula> C. Devices were fabricated using Air Force Research Laboratory’s (AFRL’s) 140-nm <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</i> -gate process technology. The performance degradation measured in different devices was analyzed by considering changes in different device parameters and by using appropriate device physics. Cross-sectional materials characterization using scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) was performed to understand the origin of performance degradation. This understanding will allow us to design a sub- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> m GaN-based process technology compatible with HT RF applications.