A5101909614- GaN-based semiconductor devices and materials
- Semiconductor materials and devices
- Semiconductor Quantum Structures and Devices
- Ga2O3 and related materials
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- ZnO doping and properties
- Astrophysical Phenomena and Observations
- Photocathodes and Microchannel Plates
- Magnetic and transport properties of perovskites and related materials
- Graphene research and applications
- Topological Materials and Phenomena
- Gamma-ray bursts and supernovae
- Photonic and Optical Devices
- Crystallography and molecular interactions
- Iron-based superconductors research
- Multiferroics and related materials
- Semiconductor Lasers and Optical Devices
- Gas Sensing Nanomaterials and Sensors
- Silicon Nanostructures and Photoluminescence
- Advanced Condensed Matter Physics
- Semiconductor materials and interfaces
- Acoustic Wave Resonator Technologies
- Ferroelectric and Piezoelectric Materials
- Transition Metal Oxide Nanomaterials
Chinese Academy of Sciences
2005-2025
University of Chinese Academy of Sciences
2021-2025
State Key Laboratory on Integrated Optoelectronics
2015-2024
Institute of Semiconductors
1998-2024
Shanghai Micro Satellite Engineering Center
2022
Innovation Academy for Microsatellites of Chinese Academy of Sciences
2022
High Magnetic Field Laboratory
2012-2019
Hefei Institutes of Physical Science
2012-2019
Collaborative Innovation Center of Advanced Microstructures
2019
Nanjing University
2019
Abstract This paper reports the synthesis of tetragonal zirconia nanowires using template method. An as‐prepared sample was characterized by scanning and transmission electron microscopy. It found that materials were with average diameters ca. 80 nm length over 10 μm. The Raman spectrum showed peaks at 120, 461, 629 cm –1 , which are attributed to E g B 1g phonon modes structure, respectively. UV‐vis absorption an peak 232.5 (5.33 eV in photon energy). Photoluminescence (PL) spectra a strong...
As a novel X-ray focusing technology, lobster eye micro-pore optics (MPO) feature both wide observing field of view and true imaging capability, promising sky monitoring with significantly improved sensitivity spatial resolution in soft X-rays. Since first proposed by Angel (1979), the have been extensively studied, developed trialed over past decades. In this Letter, we report on first-light results from flight experiment Lobster Eye Imager for Astronomy ($LEIA$), pathfinder wide-field...
We analyzed the protective ability of chemical vapor deposition (CVD) graphene domains against corrosion Cu surfaces. Fresh various shapes were ideal corrosion-inhibiting layers. However, obvious was found within exposed to air for over a week. Our work demonstrates that opportunities CVD provided by wrinkles but not others, such as grain boundaries and domain boundaries, which are always believed primary factor inferior quality at present.
Small-size, high-density, and vertical-ordering Ge quantum dots are observed in strained Si/Ge short-period superlattices grown on Si(001) at low growth temperature by molecular-beam epitaxy. The photoluminescence (PL) peak position, the strong PL room temperature, high exciton binding energy suggest an indirect-to-direct conversion of dots. This is good agreement with theoretical prediction. characteristic absorption directly indicates this conversion. tunneling carriers between these also observed.
Abstract In the past few years, many groups have focused on research and development of GaN-based ultraviolet laser diodes (UV LDs). Great progresses been achieved even though challenges exist. this article, we analyze developing diodes, approaches to improve performance diode are reviewed. With these techniques, room temperature (RT) pulsed oscillation AlGaN UVA (ultraviolet A) LD has realized, with a lasing wavelength 357.9 nm. Combining suppression thermal effect, high output power 3.8 W...
In the cathode luminescence spectroscopic study of AlN thin films grown on c-plane sapphire, we found that 3–4 eV is correlated with O impurities, and it first enhanced then weakened increase in temperature. The results an SIMS test show concentration impurities samples weakly growth conditions but strongly surface roughness at time growth. rougher exposes more crystalline plane to environment different planes have absorption capacities for leading inhomogeneous distribution AlN. This a...
The optical properties of aluminum nitride (AlN) materials were investigated using cathodoluminescence (CL), revealing two deep-level related emission peaks located at 340 nm and 380 nm. These are similar to the "yellow luminescence peak" observed in GaN materials. By increasing acceleration voltage, it was found that intensity these remained unchanged initially then increased. Additionally, an increase injected current led emergence a new peak 320 tests indicated emissions oxygen atoms...
Relaxed GexSi1−x epilayers with high Ge fractions but low threading dislocation densities have been successfully grown on Si (001) substrate by employing a stepped-up strategy and set of low-temperature GeySi1−y buffers. We show that even if the fraction rises up to 90%, density can be kept lower than 5×106 cm−2 in top layers, while total thickness structure is no more 1.7 μm.
We report the discovery of superconductivity at $\ensuremath{\sim}9$ K in Fe${}_{1.05}$Te single crystals that have been exposed to air for more than six months. The is induced due oxygen incorporation and only exists surface layer samples. Our high-resolution transmission electron microscopy experiments density functional theory calculations show prefers locate interstitial site Fe-Te layer. X-ray photoelectron spectra characterize an enhancement itinerant character Fe $3d$ electrons, which...
Tunable symmetry breaking plays a crucial role for the manipulation of topological phases quantum matter. Here, through combined high-pressure magnetotransport measurements, Raman spectroscopy, and x-ray diffraction, we demonstrate pressure-induced phase transition in nodal-line semimetal ZrSiS. Symmetry analysis first-principles calculations suggest that this may be attributed to weak lattice distortions by nonhydrostatic compression, which breaks some crystal symmetries, such as mirror...
Temperature characteristics of GaN-based laser diodes are investigated. It is noted that the characteristic temperature threshold current ( T 0 ) decreases with decreasing lasing wavelength for LDs. The performance deteriorates seriously UV LDs at high temperature. ascribed to increase carriers escaping from quantum wells due lower potential barrier height. In this Letter, AlGaN used as layer in instead GaN improve and slope efficiency by increasing height wells. Based on structure, a output...
A Sb-mediated growth technique is developed to deposit Ge quantum dots (QDs) of small size, high density, and free dislocations. These QDs were grown at low temperature by molecular beam epitaxy. The photoluminescence absorption properties these suggest an indirect-to-direct conversion, which in good agreement with a theoretical calculation.
The performance of ultraviolet (UV) laser diodes (LDs) with a low Al mole fraction AlGaN cladding layer was investigated by varying the thicknesses waveguide layer. It is found that (1) loss carriers in much larger than blue or green LDs due to shallower quantum well and consequently weaker carrier confinement UV lasers. (2) Carrier can be suppressed using thinner Therefore, threshold current reduced. (3) GaN/AlGaN single lasing at 366 nm are fabricated relatively thin layers layers.
The reaction between gallium (Ga) and silicon (Si), termed melt-back etching, greatly deteriorates the quality of GaN grown on a Si substrate. In this paper, mechanism etching was investigated layer-by-layer in GaN/AlN/Si system. It is found that environment reactor plays critical role which may happen as early during baking process. Drawing experimental evidence analyses, two-step model proposed. Finally, optimized pretreatments including an AlN precoating process reduction temperature were...
Here, we demonstrate the Altshuler-Aronov-Spivak (AAS) interference of topological surface states on exfoliated Bi2Te3 microflakes by a flux period h/2e in their magnetoresistance oscillations and its weak field character. Both with h/e are observed. The h/2e-period AAS oscillation gradually dominates increasing sample widths temperatures. This reveals transition Dirac Fermions’ transport to diffusive regime.
Hall, current–voltage, and deep-level transient spectroscopy measurements were used to characterize the electrical properties of metalorganic chemical vapor deposition grown undoped, Er- Pr-implanted GaN films. Only one deep level located at 0.270 eV below conduction band was found in as-grown However, four defect levels 0.300, 0.188, 0.600, 0.410 Er-implanted films after annealing 900 °C for 30 min, 0.280, 0.190, 0.610, 0.390 1050 min. The origins are discussed.
Abstract The relationship between stress and dislocation density in MOCVD epitaxial AlN was studied. It has been found that the aluminum nitride (AlN) layer generates tensile when crystal islands are merged. By controlling size of at end 3D growth, generated during epitaxy can be effectively reduced. Mechanical calculations show there is a linear edge thread dislocations growth. growth below 0.1 Gpa, high-quality sample with an 6.31 × 10 7 cm −2 obtained.
Vacuum ultraviolet (VUV) photodetectors are essential for applications in space science, semiconductor lithography, and life science. In this study, we present what believe to be a novel AlN-based VUV Pt-AlN Schottky barrier photodetector fabricated on sapphire substrate. This device comprises an i-AlN/n-AlGaN layer structure ingeniously utilizes n-AlGaN metal establish ohmic contact, addressing the challenge of n-type doping AlN. Experimental results demonstrate peak response 0.06A/W at 194...
Indium antisite defect InP-related photoluminescence has been observed in Fe-diffused semi-insulating (SI) InP. Compared to annealed undoped or Fe-predoped SI InP, there are fewer defects InP obtained by long-duration, high-temperature Fe diffusion. The suppression of the formation point can be explained terms complete occupation at indium vacancy. is enhanced interstitial that caused kick out In and substitution site diffusion process. Through these Fe-diffusion results, nature better understood.
The influence of growth interruption on the surface and luminescence properties AlGaN/GaN ultraviolet multi-quantum wells (UV MQWs) is investigated. It found that when well barrier layers MQW samples are continuously grown at same temperature, they have lower edge dislocation density flatter MQWs compared to with interrupted growth. Moreover, continuous more conducive improving efficiency MQWs. This phenomenon attributed impurity incorporation induced by interruption, while a can reduce...
We observe an unusual combination of normal and superconducting state properties without any signature strong spin fluctuations in single-crystal Ir${}_{3}$Te${}_{8}$. The electrical resistivity does not saturate by 700 K but exhibits a low-resistivity ratio, it two extended linear regimes (approximately 20--330 370--700 K) with the same slope, separated small hysteretic interval marking first-order phase transition from cubic to rhombohedral lattice symmetry at ${T}_{\mathrm{S}}$ = 350 K....