- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Growth, structural, Hirshfeld surface, optical, laser damage threshold, dielectric and chemical etching analysis of 4-dimethylaminopyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP)?single crystal
摘要： The organic 4-dimethylaminopyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP) single crystal was grown by slow evaporation solution growth technique at 35 °C. The single crystal X-ray diffraction analysis confirms that the grown crystal belongs to the orthorhombic crystal system with the space group of P212121. Different functional groups were affirmed using FT-IR and FT-Raman analysis. The intermolecular interactions of the DMAPNP molecule were executed using Hirshfeld surface study. The Mulliken atomic charge population analysis was performed using density functional theory (DFT). The bonding interactions between two orbital atoms and groups were executed by the density of state (DOS). The optical transmittance study shows that the grown crystal has 60 to 78% transmittance in the Vis–NIR region. It has an emission peak at 482 nm in the photoluminescence (PL) spectrum. The photoconductivity analysis shows that the DMAPNP has negative photoconductive behavior. The thermal stability of the DMAPNP crystal was investigated by TG–DTA analysis. The etch pit density of the title crystal was investigated using chemical etching study. The mechanical stability of the DMAPNP crystal was tested by Vickers microhardness tester. Laser damage threshold analysis reveals that the DMAPNP is stable up to 10 mJ of laser power. The dielectric properties were assessed and the electronic polarizability of the DMAPNP was evaluated by the different empirical relations. The second harmonic generation (SHG) efficiency of DMAPNP crystal was measured by Kurtz–Perry powder technique.
关键词： optical,4-dimethylaminopyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP) single crystal,Growth,chemical etching analysis,dielectric,Hirshfeld surface,structural,laser damage threshold
更新于2025-09-16 10:30:52
-
[IEEE 2018 37th Chinese Control Conference (CCC) - Wuhan (2018.7.25-2018.7.27)] 2018 37th Chinese Control Conference (CCC) - Silicon Melt Liquid Level Detection Based on Improved Laser Trigonometry
摘要： In order to improve the robustness of laser triangulation to detect the liquid level of silicon melt, this paper ?rstly proposes a method of calculating the laser spot coordinates based on the voting mechanism. The vote is taken according to the coordinates of small laser spots, which are formed by the effect of liquid surface ?uctuation on the line laser in the liquid level measurement image. Secondly, the Kalman ?lter method is used to correct the liquid level measurement data and compensate the missing data. Then the linear conversion is performed to obtain the liquid level value. Finally, the experimental results show that this method can effectively improve the robustness of the liquid level measurement by the laser triangulation method, and avoid the generation of impulse noise. The introduction of the Kalman ?lter can accurately correct the level measurement data and compensate for missing data.
关键词： Single crystal furnace,Kalman ?lter,Coordinate calculation,Voting mechanism,Liquid level detection
更新于2025-09-16 10:30:52
-
Through Concentration Profiling of Heterojunction Solar Cells
摘要： Electrochemical capacitance–voltage profiling has been used to examine heterojunction solar cells based on single-crystal silicon. Specific features of the electrochemical capacitance–voltage profiling of modern multilayer heterojunction solar cells have been analyzed. The distribution profiles of majority carriers across the whole thickness of the samples were obtained, including, for the first time, those in layers of conducting indium tin oxide.
关键词： electrochemical capacitance–voltage profiling,single-crystal silicon,amorphous silicon,heterojunction solar cells
更新于2025-09-16 10:30:52
-
Subsurface damage and phase transformation in laser-assisted nanometric cutting of single crystal silicon
摘要： Single crystal Si subsurface damage and phase transformation caused by laser-assisted nanometric cutting were investigated in this paper through the ultraprecision cutting experiments and molecular dynamics simulation. Post-cutting examination of a crystal’s subsurface revealed a distorted Si-I layer and an amorphous Si with embedded nanocrystalline Si-III and Si-XII. As a result of insufficient contact pressure during laser-assisted cutting, the amorphous Si was directly generated from the Si-I through the collapse of the crystal lattice rather than from the intermediate high-pressure phase Si-II. The newly-formed amorphous Si crystallized partially during the laser-assisted cutting and transformed into metastable Si-III and Si-XII phases caused by the laser annealing effect. In comparison to machining without laser assistance, it was found that dislocation activity was increased by a factor of ~8×1014 when laser assistance was applied. This gave rise to enhancement of plastic deformability of the material, with the critical ductile-brittle transition depth of cut increasing from 150 nm to 395 nm and the thickness and extent of stress in the distorted Si-I subsurface layer being reduced.
关键词： single crystal silicon,laser assisted,phase transformation,nanometric cutting,subsurface damage
更新于2025-09-16 10:30:52
-
Near-Infrared Organic Single-Crystal Nanolaser Arrays Activated by Excited-State Intramolecular Proton Transfer
摘要： Near-infrared lasing beyond 760 nm is achieved in the organic nanowire arrays made from the ESIPT-active organic molecule of (E)-3-(4-(dimethylamino)phenyl)-1-(1-hydroxynaphthalen-2-yl)prop-2-en-1-one, and the dynamic intramolecular proton transfer process within ～2.5 ps is verified. The single-mode NIR lasing high-quality factor Q of ～2,340 can be achieved from a single nanowire with L = 10 mm, and the multi-mode NIR lasing with the lasing threshold of 2.2 mJ cm?2 can be achieved from a single nanowire with L = 70 mm.
关键词： Organic Single-Crystal,Near-Infrared,Nanolaser Arrays,Excited-State Intramolecular Proton Transfer
更新于2025-09-16 10:30:52
-
Size-controlled Patterning of Single-crystalline Perovskites Arrays toward Tunable High-performance Microlaser
摘要： Single-crystalline halide perovskites with regular morphology are of great significance for laser applications because they can be used to fabricate a natural whispering-gallery-mode resonator. Although enormous efforts have been put to synthesize single-crystalline perovskites, controlling the lateral size and thickness of the crystal, particularly at the nanoscale, is still challenging. Here, we report a facile and high-throughput strategy to selectively one-step create micro/nanoscale size-controlled all-inorganic perovskite single-crystal arrays by surface-tension-confined evaporative assembly. Our method can be used to easily tune the single crystal size and selectively position the single crystal, with versatility in fabricating perovskite single-crystal arrays in wafer scale. When the patterned size increases from 2 to 25 μm, the width of the CsPbClBr2 perovskite microplates increased from 150 nm to 4.2 μm. Fixing the width of the microplates at 1.6 μm, with the increase of the sliding speed from 50 to 250 mm/min, we could significantly control the thicknesses from 270 nm to 430 nm. Additionally, our present study provides a characterization of lasers based on different three-dimensional structures, confirming their width-dependence lasing mode and thickness-dependence lasing threshold characteristic, which is beneficial for the tunability of high-performance microlaser.
关键词： microlaser,surface-tension-confined,single crystal,halide-perovskite,evaporative assembly
更新于2025-09-12 10:27:22
-
Investigation of Crystallization Process of a Single Crystal Nickel-Based Alloy during the Laser Multilayer Cladding
摘要： The article shows the results of multilayer laser cladding of heat-resistant single crystal nickel-based alloy ZhS32-VI (CSMX-4 analogue). The influence of the main technological parameters on geometry and microstructure formation of deposited beads was investigated. Based on obtained dependencies, the regression equations are compiled for describing the shape of bead and the ratio of directional and equiaxial crystallized sections. The obtained dependencies of regime parameters nomination allow restoring the gas-turbine blades by the method of laser cladding.
关键词： gas-turbine blades,heat-resistant nickel-based alloys,laser cladding,crystallization,single crystal nickel-based alloys
更新于2025-09-12 10:27:22
-
Growth, structure, and spectroscopic properties of an Yb3+, Ho3+ co-doped LuYAG single crystal for 2.91?μm laser
摘要： Yb3+ and Ho3+ co-doped Lu2.55Y0.45Al5O12 (Yb,Ho:LuYAG) crystal with a size of Φ 28 mm × 120 mm was successfully grown by the Czochralski method. The lattice parameters of the as-grown Yb,Ho:LuYAG crystal were obtained by Rietveld refinement with the XRD data. The result of X-ray rocking curve indicated that the grown crystal has a high crystalline quality. From strong absorption band near 935 nm and emission bands within 2700–3000 nm, we found that the Yb3+ ions can be acted as the sensitizer for the activator ions Ho3+. Furthermore, the lifetimes of the 5I6 and 5I7 levels of the Ho3+ ions were 68.25 μs and 7.58 ms, respectively. These results indicated that the Yb,Ho:LuYAG crystal is a promising gain material for 2.91 μm laser pumped by a 940 nm LD.
关键词： LuYAG,Ho3+,Yb3+,single crystal,2.91 μm laser
更新于2025-09-12 10:27:22
-
Single‐Crystal Red Phosphors: Enhanced Optical Efficiency and Improved Chemical Stability for wLEDs
摘要： Crystal phosphors have many unique advantages compared with powdery ones. Herein, room-temperature-grown millimeter-sized single-crystal phosphors of Cs2XF6:Mn4+ (X = Ge, Si, and Ti) with remarkably higher external quantum efficiency than the corresponding powdery samples are reported. In addition, as compared with the powdery ones, the crystal samples exhibit much better stability toward water under different pH conditions. The red light-emitting diodes (LEDs) based on Cs2XF6:Mn4+ crystals show significantly improved luminous efficiency than those based on their corresponding powders. An assembled white LED device composed of the two layers of phosphors, i.e., the crystal (such as Cs2GeF6:Mn4+) and commercial Y3Al5O12:Ce3+, on a blue chip exhibits intense warm white light with high luminous efficiency (up to 193 lm W?1), high color rendering indexes (88), and low correlated color temperatures (3107 K). Hence, these crystals with greatly improved efficiency and stability can be potentially applied in high-quality LED backlighting display and white LED lighting, especially inside the micro-LED devices.
关键词： single-crystal phosphors,enhanced optical efficiency,photoluminescence,improved chemical stability,light-emitting diodes
更新于2025-09-12 10:27:22
-
Single-mode infrared-fiber waveguide on ZnSe single crystal
摘要： We report on the fabrication of planar and channel single mode waveguide operating at infrared-fiber band in ZnSe single crystal by using 6.0 MeV C and O ion implantation and standard lithography technique. The effective refractive indices of the planar waveguide mode at 1539 nm is recorded using the prism-coupling method at the dark environment. Near field intensity distributions of the single mode in ZnSe single crystal waveguide at 1539 nm are measured by an end-face coupling system and reconstructed by the finite difference beam propagation method, respectively. Micro-Raman spectrometry is used to analyze microstructural changes of the substrate and waveguide structure.
关键词： lithography technique,single mode,infrared-fiber waveguide,ZnSe single crystal,ion implantation
更新于2025-09-11 14:15:04