Jiandong Ye

• Australian National University

By first-principles, we study the magnetic properties of (Mn, N)-codoped ZnO, with various interstitial structures of H. Besides, hydrogen motion in ZnMnON has been investigated too. Results show that a mobile H in (Mn, N)-codoped ZnO may be favorably formed a stable –Mn–H–N– complex, and that the ferromagnetism strongly depends on the geometrical...

The enhancement of photo-response in nanometer-scale germanium photodetectors through bull’s eye antennas capable of supporting 2nd-order Bloch surface plasmon modes is demonstrated in theory and experiment. A detailed numerical investigation reveals that the presence of surface wave and its constructive interference with the directly incident ligh...

ZnO:Mn films doped with indium (In) and nitrogen (N) have been grown on sapphire and ZnO template substrates, respectively by the metal-organic chemical vapor deposition method. All these samples show clear hysteresis loops and saturation magnetizations (MS) at room temperature characterized by a vibrating sample magnetometer in a Quantum Design Ph...

We studied the structural properties, defect formation, and thermal stability of H in hydrothermally grown ZnO single crystals implanted with H- dose ranging from 2.5×1016 to 1×1017 cm−2. H implantation is found to create deformed layers with a uniaxial strain of 0.5–2.4% along the c-axis in ZnO, for the low and high dose, respectively. About 0.2–0...

Effect of the V/III ratio during buffer layer growth on the yellow and blue luminescence in undoped GaN epilayer has been studied by means of photoluminescence spectroscopy and high resolution X-ray diffraction. It is found that the densities of screw and edge threading dislocations increase with the V/III ratio of the buffer layer, and the intensi...

Polarization engineering can enable high-density two-dimensional electron gas (2DEG) at the interface of ferroelectric/non-polar κ-Ga2O3/β-Ga2O3 hybrid polymorph structures, whereas the formation of a disordered intermediate layer has prevented the experimental observation of 2DEG, with phase transition being the primary obstacle. In this work, we...

Ultra-wide bandgap (UWBG) NiO/β-Ga2O3 p–n junction has recently emerged as a key building block for emerging electronic and optoelectronic devices. However, the long-term reliability of this bipolar junction remains elusive. Here, the temporal evolution of the transient parametric shift is characterized in this junction under the prolonged forward-...

Orientation-dependent substrates provide effective platforms for achieving α-Ga2O3 with low dislocation densities, whereas the associated strain and dislocation dynamics have not been fully explored. Herein, we investigated the evolution of growth mode, interfacial strain, and dislocation propagation in the α-Ga2O3 epitaxial layer with various orie...

High-responsivity and energy-saving ultraviolet photodetectors become crucial components for modern optoelectronic information sensing and communication systems. This study presents an advanced self-powered MXene/GaN Schottky ultraviolet photodetector that features a high-quality van der Waals interface to enhance photoresponsivity. The photodetect...

Power devices rely on ideal edge termination to suppress the electric field crowding and avoid premature breakdown before the material's critical field is reached. In this work, a hybrid electric field management configuration, featuring the combination of beveled-mesa (BM) termination and high-k oxide BaTiO3 field plate (FP), was implemented in Ga...

In this work, high-performance ultraviolet (UV) phototransistors (PTs) based on the p-GaN/AlGaN/GaN HEMT structure were reported. An innovative strategy making a tradeoff between the absorption thickness of the incident light and the retraction distance of the depletion region was developed for the first time. The optimal PTs exhibited a large phot...

In this article, the origin of severe drain–source current kink effect in $\beta $ -Ga $_{\text{2}}$ O $_{\text{3}}$ MOSFETs has been exploited by means of temperature-and pulse-dependent current–voltage ( $\textit{I}$ – $\textit{V}\text{)}$ analysis. By reducing the pulse biasing widths, whereby the self-heating effect was negligible, the ou...

In this work, the optical transition of self‐trapped excitons (STEs) and the emergent green emission in β‐Ga2O3 samples with/without Sn impurities at various doping levels have been investigated via temperature‐ and power‐dependent photoluminescence. The ultraviolet (UV) emissions ≈ 3.40 eV unanimously exhibit an excitonic nature related to STEs an...

Avalanche capability is an essential robustness of power devices for system applications. Edge termination (ET) is the key design to enable avalanche as it allows the device junction to reach the material’s avalanche field ( E_AVA ) without premature breakdown. Avalanche ET design is very difficult in ultra-wide bandgap (UWBG) devices du...

This work demonstrates ultrathin-body GaN HEMTs on 6-inch sapphire substrate with robust irradiation hardness against prompt dose rate (PDR) and single-event effect (SEE). By implementing low-temperature physical vapor deposition and high-temperature metalorganic chemical vapor deposition growth technologies, the GaN channel layer is directly grown...

Unintentionally doped carbon impurities from organometallic precursors are primary sources of carrier compensation and mobility degradation in wide bandgap semiconductors, leading to lowered performance of power electronic devices. To address this challenge, carbon-free α-Ga2O3 single-crystalline thin films were heteroepitaxially grown on sapphire...

Power Schottky barrier diodes (SBDs) face an inherent trade-off between forward conduction loss and reverse blocking capability. This limitation becomes more severe for ultra-wide bandgap (UWBG) SBDs due to the large junction field. A high Schottky barrier is usually required to suppress the reverse leakage current at the price of an increased forw...

In this article, we present AlGaN/GaN-based lateral Schottky barrier diodes (SBDs) on sapphire substrate with fully recessed anodes and a $\vphantom{_{\int}}$ high-permittivity field plate (FP). A specific ON-resistance of 3.2 m $\Omega$ $\cdot$ cm $^{\text{2}}$ , an on/off current ratio of 10 $^{\text{10}}$ , and a reverse breakdown voltage...

Terahertz (THz) communication is a rapidly advancing field with applications spanning space exploration, wireless communication, and security checks. Achieving effective intensity modulation of THz radiation is a crucial requirement for THz technology. In this study, we propose an approach to achieve real-time and precise control over THz radiation...

In this work, fine carrier transport and recombination processes in p-NiO gate AlGaN/GaN high electron mobility transistors were investigated by analyzing their electroluminescence under forward gate bias, with photoluminescence spectrum as a reference. Red luminescence with a peak of 1.9 eV was captured when the gate bias voltage exceeded 4 V, whi...

In this work, we propose combining a low work function anode metal and junction barrier Schottky structure to simultaneously achieve low turn-on voltage (Von) and high breakdown voltage (BV), which alleviates the dilemma that high BV requires high Schottky barrier height (SBH) and high Von. Molybdenum (Mo) is used to serve as the anode metal to red...

Impacts of spatial charge inhomogeneities on carrier transport fluctuations and premature breakdown were investigated in Schottky ampere-class Ga2O3 power diodes. Three prominent electron traps were detected in Ga2O3 epilayers by a combination of the depth-resolved capacitance spectroscopy profiling and gradual dry etching. The near-surface trap oc...

In this Letter, we investigated the electrostatic control capability and gate reliability of the BaTiO3 integrated AlGaN/GaN HEMTs. The fabricated HEMT exhibits a high peak maximum transconductance of 141 mS/mm, a large ON/OFF current ratio of 4.1 × 10⁹, and a small subthreshold swing of 70.6 mV/dec, attributed to the gate leakage suppression and p...

Addressing microstructural domain disorders within epitaxial β-Ga2O3 is critical for phase engineering and property improvement, whereas the associated evolution of β-Ga2O3 heteroepitaxial domains remains largely unexplored. In this Letter, we conducted a quantitative investigation of microstructural domains in (−201)-oriented epitaxial β-Ga2O3 fil...

This study examines the electronic and luminescent properties of β-(AlxGa1−x)2O3 (0 ≤ x ≤ 0.42) thin films grown on (0001) sapphire using laser-MBE, with a focus on the evolution of defect energy levels and their impact on surface Fermi level pinning and luminescence. X-ray photoelectron spectroscopy (XPS) and cathodoluminescence (CL) have been emp...

In this letter, we report on a quasi-vertical GaN-based metal-insulator-semiconductor (MIS) Schottky barrier diode with an insertion of 2 nm thick Al 2 O 3 dielectric layer. It shows a turn-on voltage of 0.7 V, a specific on-resistance of 3.5 mΩ·cm ² , and a high on/off current ratio of 10 ¹¹ . The proposed structure enables a breakdown voltage of...

In this work, we have designed a novel gas inlet structure for efficient usage of growth and doping precursors. Our previous gas injection configuration is that the gas is mixed to one pipe first, then divided into two pipes, and finally entered the chamber symmetrically above the substrate without a jet nozzle. The distance between gas inlet and s...

Heterointegrated Ga2O3-on-SiC radio-frequency (RF) MOSFETs with record-high frequency performances were reported. A two-dimensional electron gas like channel with a high electron concentration and decent mobility was formed through the shallow implantation of Si into the $\beta $ -Ga2O3 (−201) nanomembrane integrated on the highly thermal conduct...

Highly stable threshold voltage ( $\textit{V}_{\text{TH}}\text{)}$ characteristics are an essential reliability requirement for p-GaN/AlGaN/GaN high-electron-mobility transistors (p-GaN HEMTs) to withstand various gate bias stresses for power applications. In this work, we demonstrate high- $\textit{V}_{\text{TH}}$ (3.0 V) p-GaN HEMTs with robust...

Avalanche and surge robustness involve fundamental carrier dynamics under high electric field and current density. They are also prerequisites of any power device to survive common overvoltage and overcurrent stresses in power electronics applications such as electric vehicles, electricity grids, and renewable energy processing. Despite tremendous...

We report radio-frequency (RF) MOSFETs with a two-dimensional-electron-gas-like (2DEG-like) channel formed at the $\beta $ -Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> surface throu...

A novel design of the gas inlet system in a diamond microwave plasma chemical vapor deposition growth chamber has been reported in this paper. The design is targeting for high-quality, high-speed, and high-efficiency diamond material fabrication. By introducing a gas inlet hole into the susceptor, we expand the ways of gas introduction for diamond...

Single-photon emitters based on intrinsic defects in silicon carbide (SiC) are promising as solid-state qubits for the quantum information storage, whereas defect engineering in a controllable manner still remains challenging. Herein, the thermally-driven defect dynamic reaction in the ion implanted 4H-SiC has been exploited through the optical emi...

In this Letter, the trap inhomogeneity within β-Ga 2 O 3 is correlated with the conversion of Shockley–Read–Hall (SRH) recombination in NiO/ β-Ga 2 O 3 p ⁺ –n heterojunction diodes. For the virgin epi-wafer, both near-surface traps E2 (E C -0.82 eV) and E3 (E C -1.11 eV) and bulk E2 * traps (E C -0.76 eV) are identified by a transient capacitance a...

Metal-semiconductor-metal (MSM) architectures are popular in achieving high-responsivity Ga 2 O 3 solar-blind photodetectors (SBPDs), whereas the hot-electron-induced internal photoemission (IPE) effect restricts the detecting performance. Herein, we demonstrate the rational design of an Al/Al 2 O 3 /Ga 2 O 3 metal-insulator-semiconductor (MIS) SBP...

The authors demonstrate the enhanced light output from 275-nm AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED) structures via the in-plane modulation of shallow photonic crystal (PC) patterns that were fabricated on the p-AlGaN contact layer surface. The employed PC lattice constants are in the range of 270–780 nm, much larger than the...

The co-doping mechanism of boron and oxygen substitutional complexes in diamond are investigated since the B-O co-doping seems to be a solution for preparing n-type diamond in some experiments. We use first-principles calculations to predict the geometry of a range of B-O complexes in diamond. Three possibly stable configurations are confirmed thro...

We successfully fabricated a high-performance $\varepsilon $ -Ga $_{\text{2}}$ O $_{\text{3}}$ solar-blind photodetector employing an interdigital structure. The device exhibits a prominent response peak at 240 nm with a cutoff edge located at 266 nm. Notably, the solar-blind ultraviolet (UV) in-band/ out-of-band rejection ratio reaches 10 $^{\...

High-performance GaN based one-chip direct coupled field-effect-transistor logic (DCFL) circuits were demonstrated, in which enhancement-mode (E-mode) GaN high electron mobility transistors (HEMTs) were formed simultaneously with depletion-mode (D-mode) components through the selective-area growth of p-NiO gates at room temperature by sputtering. T...

The construction of p-NiO/n-Ga2O3 heterojunction becomes a popular alternative to overcome the technological bottleneck of p-type Ga2O3 for developing bipolar power devices for practical applications, whereas the identification of performance-limiting traps and the bipolar transport dynamics are still not exploited yet. To this end, the fundamental...

To understand and control thermal conductance of interface between metal and semiconductor has now become a crucial task for the thermal design and management of nano-electronic and micro-electronic devices. The interfacial alignments and electronic characteristics of the interfaces between metal and semiconductor are studied using a first-principl...

A weak negative thermal quenching (NTQ) effect of nitrogen vacancy centers in nitrogen-doped diamond is investigated by low-temperature photoluminescence technology. Results show that a weak NTQ phenomenon of the NV⁻ centers was observed in the range of 10–40 K. Aiming to explain the observed NTQ effect, three hypotheses are proposed to classify th...

To solve the inefficiency of optical out-coupling of the nitrogen-vacancy (NV) luminescence in bulk diamond, we propose a quantum-spin sensor based on the NV centers in diamond. The sensor is able to map out the microwave magnetic field or temperature and other distributions on a sub-micron scale. We demonstrate the implementation of a nanowire (NW...

The application of p-type oxide typified with NiOx as cap layer in AlGaN/GaN HEMT for normally-off operation has specific benefits, including etching free fabrication process, high hole density and elimination of Mg dopants diffusion effects. This work presents a device configuration exploration combining the p-NiOx gate cap layer and a thin AlGaN...

This work proposed to change the structure of the sample susceptor of the microwave plasma chemical vapor deposition (MPCVD) reaction chamber, that is, to introduce a small hole in the center of the susceptor to study its suppression effect on the incorporation of residual nitrogen in the MPCVD diamond film. Using COMSOL multiphysics software simul...

The authors demonstrate a Bull’s eye cavity design that is composed of circular Bragg gratings and micropillar optical cavity in 4H silicon carbide (4H-SiC) for single photon emission. Numerical calculations are used to investigate and optimize the emission rate and directionality of emission. Thanks to the optical mode resonances and Bragg reflect...

Schottky Barrier Diodes GaN is a promising candidate for next‐generation power electronic devices, but its potential is far from being realized. In article number 2107301, Peng Chen, Rong Zhang, Youdou Zheng, and co‐workers demonstrate a high power figure‐of‐merit, 10.6‐kV AlGaN/GaN lateral Schottky barrier diode with single channel, and sub‐100‐μm...

Pursuing nanometer-scale nonlinear converters based on second harmonic generation (SHG) is a stimulating strategy for bio-sensing, on-chip optical circuits, and quantum information processing, but the light-conversion efficiency is still poor in such ultra-small dimensional nanostructures. Herein, we demonstrate a highly enhanced broadband frequenc...

In this Letter, we report on the enhanced radio frequency (RF) performance in sub-micrometer scaled β-Ga 2 O 3 tri-gate FinFETs. With a 200-nm-thick β-Ga 2 O 3 bulk channel and a 0.35 μm gate length, the FinFETs exhibit an improved current-gain cutoff frequency of 5.4 GHz and a maximum oscillation frequency of 11.4 GHz, which are 20% and 58% improv...

The metal-semiconductor-metal (MSM) structure is a popular architecture for developing Ga2O3 solar-blind photodetectors. The nature of metal-semiconductor contact is decisive for the operation mode, gain mechanism, and device performances. In this contribution, κ-Ga2O3 MSM solar-blind photodetectors with Ti/Ga2O3 Ohmic and Ni/Ga2O3 Schottky contact...

We report a GaN-based Schottky barrier diode with a p-NiO field ring and field plate. It shows a low turn-on voltage ( V ON ) of ∼0.6 V, an On-resistance ( R ON ) of ∼6.5 mΩ·cm ² , a nearly unity ideality factor of 1.13 at V F = 0.3 V, and a high on/off current ratio of ∼10 ¹⁰ . The breakdown voltage (BV) is increased from 300 to 1100 V, rendering...

Solar desalination is expected to solve the problem of global water shortage. Yet its stability is plagued by salt accumulation. Here, a paper-based thermal radiation-enabled evaporation system (TREES) is demonstrated to achieve sustainable and highly efficient salt-collecting desalination, featuring a dynamic evaporation front based on the accumul...

Ferroelectric-semiconductor heterostructures offer an alternative strategy to manipulate polarization towards advanced devices with engineered functionality and improved performance. In this work, we report on the heteroepitaxial construction, band structure alignment and polarization engineering of the single-phased κ-Ga2O3/GaN ferroelectric/polar...

Epitaxial lateral overgrowth (ELO) is an effective strategy to achieve metastable phased α-Ga 2 O 3 with low dislocation densities, which is desirable for developing ultralow-loss and ultrahigh power devices, whereas the involved dislocation dynamics have not been fully exploited. In this Letter, we investigated the dislocation propagations and rea...

Identifying defects/traps is of vital importance for the implementation of high-performance Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> power devices. In this work, majority and minor...

This work acquires a vertical β-Ga 2 O 3 Schottky barrier diode (SBD) with the advanced termination structure of p-type NiO x and n-type β-Ga 2 O 3 heterojunctions and coupled field plate structures to alleviate the crowding electric field. A Ga 2 O 3 SBD delivers an average breakdown voltage of 1860 V and a specific on-resistance of 3.12 mΩ cm ² ,...

In this Letter, we demonstrate a large-area (1-mm²) beveled-mesa p-NiO/β-Ga2O3 bipolar heterojunction diode (HJD) with a high Baliga's figure of merit of 1.84 (2.87) GW/cm² from DC (pulsed) measurements. Benefiting from the suppression of electric field crowing at the designed mesa edge and bipolar current conductivity modulation, the resultant dev...

In this letter, we demonstrated a normally-off AlGaN/GaN HEMT using p-NiO as a gate stack combined with a recess structure. The fabricated HEMT exhibits a positive threshold voltage of 1.73 V, a saturation output current of 524 mA/mm, a small subthreshold swing of 79.7 mV/dec and a maximum transconductance as high as 143 mS/mm. This is the first ti...

In this work, vertical NiO/Ga2O3 heterojunction diodes (HJDs) integrated with SiNx/Al2O3 double-layered insulating field plate (FP) structures have been demonstrated. With the additional post-annealing, the resultant diode exhibits a decreased differential specific on-resistance (Ron,sp) of 5.4 mωcm2 and an enhanced breakdown voltage (BV) of 1036 V...

Owing to the advantages of ultra-wide bandgap and rich material systems, gallium oxide (Ga2O3) has emerged as a highly viable semiconductor material for new researches. This article mainly focuses on the growth processes, material characteristics, and applications of Ga2O3. Compared with single crystals and the epitaxial growth of other wide-bandga...

Heteroepitaxy of corundum-structured α-Ga2O3 and intriguing ferroelectric κ-Ga2O3 is proven as an alternative strategy to solve current challenges in heat dissipation and large-scale productivity for Ga2O3-based power electronic devices, whereas the fundamental growth dynamics and phase control of metastable Ga2O3 are still far unexplored. In this...

In this work, we demonstrated the self-powered solar-blind photodetector based on a polyaniline/α-Ga2O3 hybrid heterojunction. The resultant device exhibited distinct self-power characteristics with a peak photoresponsivity (R) of 8.2 mA/W, a UVC (UV light of wavelength range at 200–280 nm)/UVA (UV light of wavelength range at 320–400 nm) rejection...

The technical progress of Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> power diodes is now stuck at a critical point where a lack of performance evaluation and reliability validation a...

The n-type doping of diamond is quite difficult, hindering the development of diamond-based electronic devices for decades. In this work, we have designed a boron–nitrogen co-doping technique to realize n-type diamonds. Basically, the activation energy of the donors has been greatly reduced by around 50%, thanks to the successful synthesis of the b...

The construction of Ga2O3-based p-n heterojunction offers an alternative strategy to realize bipolar power devices; however, lattice mismatch usually leads to undesirable device performance and makes interface engineering more challenging. In this work, we demonstrated the construction of lattice-matched p-n heterojunctions by the in situ hetero-ep...

In this Letter, high-performance β-Ga2O3 vertical heterojunction barrier Schottky (HJBS) diodes have been demonstrated together with the investigation of reverse leakage mechanisms. In HJBS configurations, NiO/β-Ga2O3 p-n heterojunctions and p-NiO field limiting rings (FLRs) are implemented by using a reactive sputtering technique at room temperatu...

Solar-driven water evaporation, as a cost-effective and eco-friendly way to produce high-quality freshwater from saline water, is a burgeoning and promising force in the battle against global thirst. However, unsustainable vapor generation caused by salt accumulation has always plagued researchers. Here, it is revealed that a solar thermal photo va...

The generation of p-type GaN through ion implantation is an attractive proposition in the massive production of GaN-based bipolar devices, whereas the removal of implantation induced lattice disturbances and defects is a difficult exercise and hampers the conversion of conductivity in GaN. Pulsed laser annealing is an effective annealing technique...

As an ultrawide bandgap semiconductor, gallium oxide (Ga 2 O 3 ) has superior physical properties and has been an emerging candidate in the applications of power electronics and deep-ultraviolet optoelectronics. Despite numerous efforts made in the aspect of material epitaxy and power devices based on β -Ga 2 O 3 with rapid progresses, the fundamen...

Solar‐powered interfacial evaporation, a cost‐effective and ecofriendly way to obtain freshwater from contaminated water, provides a promising path to ease the global water crisis. However, solute accumulation has severely impacted efficient light‐to‐heat‐to‐vapor generation in conventional solar evaporators. Here, it is demonstrated that an interf...

In this work, gate-first technology was developed in an AlGaN/GaN high-electron-mobility transistor (HEMT) based on a high-quality in situ SiNx gate dielectric, targeting for high-stability power applications. The effect of the high-temperature annealing process on the Ni/SiNx gate stack was systematically investigated. Almost the same basic electr...

In this Letter, we report on the evolution of electronic properties governed by epitaxial misfit strain in cubic In2O3 epilayers grown on sapphire. At elevated growth temperature, the competition between the film/substrate lattice mismatch and the thermal expansion mismatch alters the macroscopic biaxial strain from compressive to tensile. Simultan...

In this letter, an anode configuration with multi-aperture structure and fully recessed AlGaN barrier layer is proposed in the AlGaN/GaN Schottky barrier diode. With the Schottky junction formed between the Ni anode metal and the channel of two-dimensional electron gas, as well as the evidently enlarged contact profile by the introduction of multip...

Engineering oxide interfaces with defined electronic band structures is of vital importance for designing all-oxide devices with controllable multifunctionality and improved performance. Here, we report the band alignment, band bending, and transport mechanism in the NiO/β-Ga₂O₃ p-n heterojunction (HJ) which exhibits high performances with a rectif...