- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Low-loss and broadband non-volatile phase-change directional coupler switches
摘要： An optical equivalent of the field-programmable gate array (FPGA) is of great interest to large-scale photonic integrated circuits. Previous programmable photonic devices relying on the weak, volatile thermo-optic or electro-optic effect usually suffer from a large footprint and high energy consumption. Phase change materials (PCMs) offer a promising solution due to the large non-volatile change in the refractive index upon phase transition. However, the large optical loss in PCMs poses a serious problem. Here, by exploiting an asymmetric directional coupler design, we demonstrate non-volatile PCM-clad silicon photonic 1 × 2 and 2 × 2 switches with a low insertion loss of ~1 dB and a compact coupling length of ~30 μm while maintaining a small crosstalk less than ?10 dB over a bandwidth of 30 nm. The reported optical switches will function as the building blocks of the meshes in the optical FPGAs for applications such as optical interconnects, neuromorphic computing, quantum computing, and microwave photonics.
关键词： Silicon photonics,Non-volatile,Optical switches,Phase-change materials,Reconfigurable photonics,Integrated photonic devices
更新于2025-09-23 15:23:52
-
Hydrogen production via a novel two-step solar thermochemical cycle based on non-volatile GeO2
摘要： Encouraged by recent advances in solar-chemical fuel production, a moderately high-temperature solar thermochemical cycle based on GeO2/Ge is investigated thermodynamically. Since the GeO2/Ge redox has a great oxygen exchange capacity and suffers unfavorable phase change at high temperature, methanothermal reduction is introduced to lower the operation temperature below melting point of redox. The calculated results indicate that reduction conditions of 875 K < T_red < 1200 K and CH4:GeO2 = 2:1 are conducive to achieving high selectivities of H2 and CO. As for the oxidation step, the H2O:Ge ratio of 8:1 is found abundant enough to ensure complete reoxidation of Ge. Isothermal and non-isothermal solar-to-fuel efficiency (η_solarfuel) are compared, where η_solarfuel of 0.47 and isothermal η_solarfuel of 0.28 respectively. In addition, the preferred site of CH4 adsorbing on GeO2 is predicted, and the calculated adsorption energy is lower than that of SnO2, indicating that GeO2 could be a suitable material for substrate before methanothermal reduction.
关键词： Non-volatile redox,Isothermal and nonisothermal operation,Syngas production,Hydrogen production,GeO2/Ge based solar-chemical cycle
更新于2025-09-23 15:23:52
-
Electric-field control of spin accumulation direction for spin-orbit torques
摘要： Electric field is an energy-efficient tool that can be leveraged to control spin–orbit torques (SOTs). Although the amount of current-induced spin accumulation in a heavy metal (HM)/ferromagnet (FM) heterostructure can be regulated to a certain degree using an electric field in various materials, the control of its direction has remained elusive so far. Here, we report that both the direction and amount of current-induced spin accumulation at the HM/FM interface can be dynamically controlled using an electric field in an oxide capped SOT device. The applied electric field transports oxygen ions and modulates the HM/FM interfacial chemistry resulting in an interplay between the spin Hall and the interfacial torques which in turn facilitates a non-volatile and reversible control over the direction and magnitude of SOTs. Our electric-field controlled spin-orbitronics device can be programmed to behave either like the SOT systems with a positive spin Hall angle or a negative spin Hall angle.
关键词： spin-orbit torques,heavy metal/ferromagnet heterostructure,spin accumulation,non-volatile control,electric field control
更新于2025-09-23 15:22:29
-
[IEEE 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Singapore, Singapore (2019.8.28-2019.8.30)] 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Non-Volatile Indium Tin Oxide Electro-Optic Switch
摘要： The abstract of the paper is not provided in the given text.
关键词： non-volatile,silicon photonics,indium tin oxide,electro-optic switch
更新于2025-09-23 15:19:57
-
Space charge limited conduction in pulsed laser deposited BaTiO3/LaNiO3 hetero-junctions
摘要： We report the charge transport mechanism in BaTiO3 (BTO) thin film deposited on LaNiO3 (LNO) buffer layer using pulsed laser deposition technique thus, forming the metal – insulator – metal junction (Au/BTO/LNO). The temperature dependent Current density- Voltage (J-V) characteristics were measured, analyzed and compared with the La0.67Ca0.33MnO3 (LCMO) buffered BTO film (Au/BTO/LCMO). Although the mechanism was found to be space charge limited conduction (SCLC) as in case of BTO/LCMO but the absence of Ohmic region in Log J-Log V plot indicates higher injection rate. Various parameters such as trap density, activation energy, and ratio of free to trapped carriers (h) were extracted out from the fitted J-V plot and subsequently their temperature dependence was studied and compared with BTO/LCMO. Higher current density, lower activation energy, lower trap density and higher ratio of free to trapped carriers (h) were observed in BTO/LNO in contrast to BTO/LCMO. Furthermore, the lower activation energy indicates the presence of shallow trap level.
关键词： Non-volatile memories,Barium titanate,Metal-Insulator-Metal junction,Space charge limited conduction,Pulsed laser deposition
更新于2025-09-23 15:19:57
-
Configurable Multi-State Non-volatile Memory Behaviors in Ti <sub/>3</sub> C <sub/>2</sub> Nanosheets
摘要： MXenes have drawn considerable attention in both academia and industry due to the attracting properties such as the combination of metallic conductivity and surface hydrophilicity. However, to the best of our knowledge, the potential use of MXenes in non-volatile resistive random access memories (RRAMs) has rarely been reported. In this paper, we have firstly demonstrated the RRAM device with the MXene (Ti3C2) as the active component. The Ti3C2-based RRAM exhibits a typical bipolar switching behavior, long retention characteristic, low SET voltage, good mechanical stability and excellent reliability. By adjusting different compliance current in the SET process, the multi-state information storage could be achieved. The charge trapping assist hopping process is considered to be the main mechanism of resistive switching of this fabricated Ti3C2-based RRAM, which is verified by conductive atomic force microscopy (C-AFM) and Kelvin probe force microscopy (KPFM). Moreover, the flexible Ti3C2-based RRAM with good mechanical stability and long retention property could be successfully fabricated using on plastic substrate. Ti3C2-based RRAM may open the door to additional applications and functionalities with the highly potential application in flexible electronics.
关键词： MXenes,non-volatile memory,flexible electronics,resistive random access memory,Ti3C2,multi-state storage
更新于2025-09-19 17:15:36
-
Femtosecond Laser-inscribed Non-volatile Integrated Optical Switch in Fused Silica based on Microfluidics-controlled Total Internal Reflection
摘要： We demonstrate a non-volatile optical power switch, fabricated by femtosecond laser inscription in a fused silica substrate, with switching operation based on microfluidics-controlled total internal reflection. The switch consists of crossed waveguides and a rectangular, high aspect ratio microfluidic channel, located at the waveguide crossing. The switching between total internal reflection and transmission at the channel wall is determined by the refractive index of the medium inside the channel. Femtosecond laser inscription allows for co-integration of low-loss optical waveguides and channels with smooth sidewalls and thus the fabrication of low insertion loss switches that are broadband and show low polarization dependent losses. The measured total internal reflection loss of the fabricated switch is about 1.5 dB at the wavelength 1550 nm. The loss due to transmission through the channel filled with refractive index matching liquid is about 0.5 dB. Detailed finite time domain and beam propagation method difference simulations of the switch’s performance indicate that the losses can be further reduced by optimizing its geometry, together with further adjusting the inscription parameters.
关键词： Fused silica,Non-volatile,Single mode waveguides,Total internal reflection,Microfluidics,Femtosecond laser inscription,integrated optical switch
更新于2025-09-19 17:13:59
-
Light-controlled molecular resistive switching ferroelectric heterojunction
摘要： Molecular ferroelectrics have attained significant advancement as a promising approach towards the development of next-generation non-volatile memory devices. Herein, the semiconducting-ferroelectric heterojunctions which is composed of molecular ferroelectrics (R)-((cid:1))-3-hydroxlyquinuclidinium chloride together with organic charge transfer complex is reported. The molecular ferroelectric domain provides polarization and bistability while organic charge transfer phase allows photo-induced charge generation and transport for photovoltaic effect. By switching the direction of the polarization in the ferroelectric phase, the heterojunction-based devices show non-volatile resistive switching under external electric field and photocurrent/voltage induced by light excitation, stable fatigue properties and long retention time. Overall, the photovoltaic controlled resistive switching provides a new route for all-organic multiphase non-volatile memories.
关键词： Molecular ferroelectrics,photovoltaic effect,heterojunctions,non-volatile memory,resistive switching
更新于2025-09-16 10:30:52
-
[IEEE 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Singapore, Singapore (2019.8.28-2019.8.30)] 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Non-Volatile Indium Tin Oxide Electro-Optic Switch
摘要： The abstract of the paper is not provided in the given text.
关键词： silicon photonics,electro-optic switch,indium tin oxide,non-volatile
更新于2025-09-12 10:27:22
-
[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - New Molecular-Based Materials for Enabling Electro-Optical Bistability in the Silicon Photonics Platform
摘要： Electro-optical bistability is a functionality which can be crucial for a wide range of applications as it can enable non-volatile and ultra-low power switching performance. We investigate the integration of a molecular-based material presenting a Spin Crossover (SCO) effect in the silicon platform for enabling optical bistability. The SCO phenomenon involves a switching process between two molecular spin states. This spin transition comes along with a change in the optical refractive index that can be switched by different external stimuli such as a variation of temperature or light irradiation and which has a hysteretic behaviour. The SCO material can be synthetized as nanoparticles so that it can be easily integrated in the silicon platform and have the potential to allow switching at room temperature.
关键词： switching,molecular material,silicon photonics,optical bistability,non-volatile
更新于2025-09-12 10:27:22