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Glass rod-sliding and low pressure assisted solution processing composition engineering for high-efficiency perovskite solar cells
摘要： High-efficiency perovskite solar cells (PSCs) have experienced rapid development and attracted significant attention in recent years. The PSCs based on doctor bladed or slot-die coated perovskite films usually have lower power conversion efficiency (PCE) than that based on spin-coated perovskite films. In this work, we have developed an effective method, called glass rod-sliding and low pressure assisted solution processing composition engineering (GRS-LPASP), to manufacture high quality perovskite film in air. GRS-LPASP composition engineering effectively increases the grain size and thickness of perovskite films and reduces the defect density by increasing the contact area between the perovskite layer and the hole transport layer, thus leading an increased current density (Jsc) of perovskite solar cells. The device with GRS-LPASP composition engineering achieves a maximum PCE of 19.78%. The experimental results demonstrates that GRS-LPASP composition engineering is a feasible method to prepare high-efficiency PSCs. Moreover, GRS-LPASP composition engineering also provides a potential approach for the commercial production of PSCs.
关键词： Low pressure assisted method,Glass rod-sliding,Perovskite film,Perovskite solar cell
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 2nd International Conference on Electronic Information and Communication Technology (ICEICT) - Harbin, China (2019.1.20-2019.1.22)] 2019 IEEE 2nd International Conference on Electronic Information and Communication Technology (ICEICT) - Hybrid Metamaterial Absorber based on the Combination of Plasmonic Structure and Magentic Absorber
摘要： This paper presents a thin-film wafer-level encapsulation process based on an epitaxial deposition seal that incorporates both narrow and wide lateral transduction gaps (0.7–50 μm), both in-plane and out-of-plane electrodes, and does not require release etch-holes in the device layer. Resonant structures fabricated in this process demonstrate high-quality factors ( f × Q products of up to 2.27e + 13 Hz) and exceptional stability (±18 ppb over one month) with no obvious aging trends. Studies on cavity pressure indicate that vacuum levels better than 0.1 Pa can be achieved after final encapsulation, thus reducing gas damping for high surface-to-volume devices. The vast diversity of functioning devices built in this process demonstrates the potential for combinations of high-performance MEMS devices in a single process and/or single chip.
关键词： high stability resonator,Wafer-level encapsulation,high quality factor,low pressure,hermetic encapsulation
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Electronics Packaging (ICEP) - Niigata, Japan (2019.4.17-2019.4.20)] 2019 International Conference on Electronics Packaging (ICEP) - An Investigation of Compound Machining of Ceramic-LPM Package by Ultrafast Laser
摘要： It is well known that ceramic substrates provide excellent electrical insulation and protection from oxidation/ corrosion in addition to idea heat dissipation while allowing heat dissipation through controlled paths, e.g. integrated heat sinks. Low pressure molding (LPM) with polyamide and polyolefin (hot- melt) materials is a process typically used to injection molding for waterproof, to encapsulate and environmentally to protect electronic components. The purpose than epoxy encapsulation is to protect electronic components with finer pitch against moisture, dust dirt and vibration. There is a special need for SiP (System in Package) application utilizing both ceramic substrate and LPM package materials where ceramic serves as mechanical structure and thermal dissipation path and LPM for high density SMT (Surface Mount) package. The research of this paper is to apply nano UV (Ultraviolet) laser to machine the LPM and ceramic substrate (sapphire, Al2O3) and compare the results with nano green laser. The interactions of these two materials with laser are quite different and even conflicting for machining (LPM is ductile and hot-melt while ceramic is brittle), thus proper strategy has to be taken to satisfy needs for both materials. One of the major problem is the re-solidification of LPM material as temperature elevated during laser irradiation. It is necessary to provide a delay time between each laser pulsing. The laser ablation threshold (LAT) of green and UV laser for both materials is also investigated in this paper. The best parameters for processing ceramic substrates are speed 200 mm/s, frequency 95 kHz, delay time 450 ms, when processing LPM speed 700 mm/s, frequency 40 kHz, delay time 250 ms.
关键词： Low Pressure Mold (LPM) compound,laser ablation threshold (LAT),ceramic substrate,ultrafast Laser
更新于2025-09-11 14:15:04
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Comparison of HPHT and LPHT annealing of Ib synthetic diamond
摘要： Defect transformations in type Ib synthetic diamond annealed at a temperature of 1870 °C under stabilizing pressure (HPHT annealing) and in hydrogen atmosphere at normal pressure (LPHT annealing) are compared. Spectroscopic data obtained on the samples before and after annealing prove that the processes of nitrogen aggregation and formation of nitrogen-nickel complexes are similar in both cases. Essential differences between HPHT and LPHT annealing are stronger graphitization at macroscopic imperfections and enhanced lattice distortions around point defects in the latter case. The lattice distortion around point defects is revealed as a considerable broadening of zero-phonon lines of "soft" (vacancy-related) optical centers. It was found that LPHT annealing may enhance overall intensity of luminescence of HPHT-grown synthetic diamonds.
关键词： nitrogen aggregation,graphitization,low pressure high temperature annealing,synthetic type Ib diamond,spectral broadening,high pressure high temperature annealing
更新于2025-09-10 09:29:36
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Effect of growth pressure on graphene direct growth on r-plane and c-plane sapphires by low-pressure CVD
摘要： Graphene was grown on both r-plane and c-plane sapphires by low-pressure chemical vapor deposition without using a metal catalyst. The growth pressure was systematically changed to investigate how the growth pressure effects the graphene growth. Consequently, it was found that the coverage of the graphene increased with increasing growth pressure on the r-plane sapphire while it decreased with increasing growth pressure on the c-plane sapphire. Raman spectroscopy and atomic force microscopy indicates that the growth layer is single-layer graphene on the r-plane sapphire while it is a bi-layer on the c-plane sapphire. Graphene is thought to grow on the r-plane sapphire simply in a two-dimensional nucleation mode. On the other hand, graphene tends to grow in the pits formed on the surface of the c-plane sapphire. The pits are thought to be produced by the oxygen desorption and have some catalytic effects.
关键词： sapphire,low-pressure CVD,atomic force microscopy,growth pressure,graphene,Raman spectroscopy
更新于2025-09-04 15:30:14
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An Automated System for Measuring the Current Density of a Pulse–Periodic Electron Beam with a Large Cross Section
摘要： In an electron source with a mesh plasma cathode on the basis of a low-pressure arc discharge, studies of the spatiotemporal stability of a pulse–periodic beam with a large cross section (750 × 150 mm2), which was extracted into the atmosphere through an output foil window, were performed. The automated system that was used in the studies allowed real-time measurements with the ability to visualize the data on a computer. This system provides an accuracy of measurements of no worse than ±2%; it differs from the known analogues in the compactness, reliability, and simplicity of its design and allows studies of the current-density distribution over the beam cross section in a wide range of beam parameters, such as the beam energy, beam current, and beam-current pulse duration. A satisfactory coincidence of the previously obtained data and the present experimental data is shown with the possibility of substantially increasing the accuracy of setting up a scientific experiment and, consequently, the speed of debugging and the reproducibility of the technological process.
关键词： automated system,pulse–periodic beam,low-pressure arc discharge,electron source,mesh plasma cathode,current-density distribution
更新于2025-09-04 15:30:14
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EXPRESS: Mid-Infrared Polarization Spectroscopy Measurements of Species Concentrations and Temperature in a Low-Pressure Flame
摘要： We demonstrate quantitative measurements of methane (CH4) mole fractions in a low pressure fuel-rich premixed dimethyl ether/oxygen/argon flat flame (Φ =1.87, 37 mbar) using mid-infrared polarization spectroscopy (IRPS). Nonintrusive in situ detection of CH4, acetylene (C2H2), and ethane (C2H6) in the flame was realized by probing the fundamental asymmetric C–H stretching vibration bands in the respective molecules in the spectral range 2970–3340 cm–1. The flame was stabilized on a McKenna-type porous plug burner hosted in a low pressure chamber. The temperature at different heights above the burner (HAB) was measured from the line ratio of temperature sensitive H2O spectral lines recorded using IRPS. Quantitative measurements of CH4 mole fractions at different HAB in the flame were realized by a calibration measurement in a low pressure gas flow of N2 with a small admixture of known amount of CH4. A comprehensive study of the collision effects on the IRPS signal was performed in order to quantify the flame measurement. The concentration and temperature measurements were found to agree reasonably well with simulations using Chemkin. These measurements prove the potential of IRPS as a sensitive, nonintrusive, in situ technique in low pressure flames.
关键词： dimethyl ether,methane,Mid-infrared polarization spectroscopy,quantitative concentrations,low pressure flame,temperature
更新于2025-09-04 15:30:14