- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Electron emission and ultraviolet electroluminescence from valence-band states and defect conduction bands of electroformed Al-Al <sub/>2</sub> O <sub/>3</sub> -Ag diodes
摘要： Electroforming of metal-insulator-metal (MIM) diodes is a soft dielectric breakdown which results in the formation of a conducting filament through the diode. It is a critical step in the development of conducting states between which switching can occur in resistive switching memories. Conduction, electron emission into vacuum (EM), and electroluminescence (EL) have been studied in two groups of electroformed Al-Al2O3-Ag diodes with amorphous anodic Al2O3 thicknesses between 20 nm and 49 nm. EM and EL appear simultaneously with the abrupt current increase that characterizes electroforming of Al-Al2O3-metal diodes. There is voltage-controlled differential negative resistance in the current-voltage (I-V) characteristics after electroforming. There is a temperature-independent voltage threshold for EM, VEM ? 4 V, where VS is the applied voltage, and there is an exponential increase of EM. There is a second exponential increase of EM in region III when VS exceeds a second temperature-independent voltage threshold, UEM. UEM is ～6.6 V for one group of Al-Al2O3-Ag diodes; it is ～7.9 V for the second group. EM is nearly constant in region II for 4 V ? VS ? UEM. Two band-pass filters have been used to characterize EL from electroformed Al-Al2O3-Ag diodes. The long-pass (LP) filter plus photomultiplier responds to photons with energies between ～1.8 eV and ～3.0 eV. The short-pass (SP) filter measures ultra-violet (UV) radiation between ～3.0 eV and ～4.2 eV. Corresponding to region I of EM, there are exponential increases of EL for VS greater than temperature-independent voltage thresholds: VLP ? 2.0 V and VSP ? 2.2 V. There is a second exponential increase of UV with the SP filter in region III for VS greater than a temperature-independent voltage threshold, USP. USP ? 7.9 V for one group of electroformed Al-Al2O3-Ag diodes and USP ? 8.8 V for the second group; USP > UEM. Both groups exhibit EM from valence band states of amorphous Al2O3. The difference in UEM and USP of the two groups of electroformed Al-Al2O3-Ag diodes is attributed to the presence or absence of a defect conduction band formed from the ground state of F0- or F+-centers, oxygen vacancies in amorphous Al2O3. The observation of exponentially increasing EM or EL in the low conductivity state of electroformed Al-Al2O3-metal diodes is not consistent with switching mechanisms of MIM diodes that involve rupture of the conducting filament since rupture that affects diode current, if it occurs, should also cut off EM and EL.
关键词： electroforming,electron emission,electroluminescence,defect conduction bands,resistive switching,Al-Al2O3-Ag diodes
更新于2025-09-23 15:22:29
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27.2: <i>Invited Paper:</i> High resolution FMM process for AMOLED displays
摘要： Fine metal mask (FMM) is one of the biggest hurdles to realize high resolution AMOLED displays for smartphone and virtual reality (VR). Various kinds of the material and processing technologies for high resolution FMMs are discussed.
关键词： Invar,Chemical Etching,VR (Virtual Reality),Electroforming,Laser patterning,FMM (Fine Metal Mask),UHD (Ultra High Definition),AMOLED
更新于2025-09-19 17:13:59
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Ultrasound-assisted electrodeposition of Fe-Ni film for OLED mask
摘要： Fe-Ni alloy is considered as the most suitable metal for OLED mask making due to its excellent properties. However, electrodeposited Fe-Ni ?lm is often companied with poor surface quality and thermal expansion. To get proper ?lm for masks making, experiments of electroforming Fe–Ni were performed with di?erent ultrasonic powers and current densities. Results show that Fe-Ni ?lm with smooth surface could be electrodeposited at high current density due to the reducing of internal stress of ?lm by ultrasonic power. The iron content, grain size, micro-hardness and Young’s modulus of ?lm all present an upward trend with ultrasonic power increases from 13 W to 93 W, and then a downward trend due to the intensively transient cavitation caused by higher ultrasonic power 120 W. With the ultrasonic power of 93 W and current density of 1 A/dm2, a good surface quality of Fe-Ni ?lms with 60.07 wt.% iron content, microhardness 351 HV, Young's modulus 167.5 GPa and CTE 3.38 × 10?6/℃ can be electrodeposited.
关键词： Fe-Ni ?lm,Electroforming,Young's modulus,Ultrasonic power,Thermal expansion
更新于2025-09-19 17:13:59
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Integral fabrication of terahertz hollow-core metal rectangular waveguides with a combined process using wire electrochemical micromachining, electrochemical deposition, and selective chemical dissolution
摘要： The application requirements of terahertz hollow-core metal rectangular waveguides with a high-working frequency have become increasingly urgent with the rapid development of terahertz technology. Integral fabrication of terahertz hollow-core metal rectangular waveguides can improve considerably the transmission performance of terahertz signals. However, with current manufacturing techniques, the high-precision integral fabrication of high-working-frequency terahertz hollow-core metal rectangular waveguides is difficult owing to their characteristically small end face size and the need for strict dimensional accuracy and high internal surface quality. In this paper, an innovative combined process of wire electrochemical micromachining, electrochemical deposition, and selective chemical dissolution is proposed firstly to overcome this puzzle. Taking the fabrication of an integral 1-THz hollow-core metal rectangular waveguide as an example, the manufacturing methods involved in each step are described particularly, together with the corresponding experimental investigations. With the end face size of 127 μm × 254 μm, edge radius less than 5 μm, and internal surface roughness less than 0.08 μm, the experimental results satisfy the design requirements for a 1-THz hollow-core metal rectangular waveguide. This study demonstrates that the proposed combined process is flexible, controllable, and suitable for the high-precision integral fabrication of high-working-frequency terahertz hollow-core metal rectangular waveguides.
关键词： Wire electrochemical micromachining,Copper micro-electroforming,Gold micro-electroplating,Terahertz hollow-core metal rectangular waveguide,High-precision integral fabrication
更新于2025-09-12 10:27:22
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Rapid Prototyping of a Micromotor with an Optical Rotary Encoder
摘要： This study proposed a rapid prototyping fabrication method for micromotors that allowed us to develop both 1 mm and 1.5 mm diameter permanent-magnet synchronous motors (PMSMs) with an optical rotary encoder. First, an integrated electroforming method was proposed for combining stator housing and flexible print circuit (FPC) coils to ease the manufacturing and assembly of micromotor components. This is particularly useful in the production of prototypes or small volumes of units. Second, an optical encoder was used to detect the rotational angle by means of a reflective code disk, an optical fiber, and a photo-detector. The micromotor was built with a code disk and an optical fiber. The code disk was designed to match the optical fiber and was made by photolithography and sputtering. Both the 1 mm and 1.5 mm diameter motors successfully achieved a rotational speed over 20,000 RPM and due to a 50 μm diameter optical fiber core, the encoders showed a resolution of 12 and 18 pulses per revolution (PPR), respectively.
关键词： micromotor,optical fiber,permanent-magnet synchronous motors,flexible print circuit,optical encoder,electroforming,rapid prototyping
更新于2025-09-10 09:29:36
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Thickness-Dependent Resistive Switching Behavior of KCu <sub/>7</sub> S <sub/>4</sub> /Cu <sub/><i>x</i> </sub> O/Au Device
摘要： We report the fabrication of KCu7S4/CuxO/Au devices with interfacial CuxO layers of different thicknesses through the spontaneous oxidation of Cu film during deposition. Deposition was conducted with an electron-beam evaporation system under the deposition rate and the chamber pressure of 0.1 ? s?1 and 9.8 × 10?3 Pa, respectively. X-ray diffraction and X-ray photoelectron spectroscopy characterizations reveal that the interfacial CuxO layers mostly comprise Cu2O and CuO. Electrical characterization reveals that the devices exhibit remarkably thickness-dependent resistive switching behavior. After undergoing an electroforming process under a high compliant current of 1000 μA, the KCu7S4/16 nm CuxO/Au device exhibits stable bipolar resistive switching behavior with the set voltage of 0.58 V and reset voltage of ?0.21 V, whereas the KCu7S4/32 nm CuxO/Au device only shows a hysteresis loop in the forward voltage regime. These findings are ascribed to the existence of high-insulation CuO, which is difficult to be softly broken down. Therefore, the depositional condition of Cu film and the thickness of the interfacial layer should be appropriately controlled for the effective performance of devices with Cu electrodes. The results may also provide guidance for the improvement of the performance and stability of Cu-based nonvolatile memory devices.
关键词： Electroforming Process,Resistive Switching Behavior,Interfacial Oxide Layer
更新于2025-09-04 15:30:14