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Nowadays there is considerable interest in the photogalvanic effect in low-dimensional devices. In this work, we built a two-dimensional Bi2C-based photodetector and explored the spin-dependent photogalvanic effect under linearly polarized light and zero-bias conditions which can produce experimentally observable photoelectron flow. It was discovered that by introducing vacancies and substitution-doping into the Bi2C photodetector, the photogalvanic effect could be enhanced by 10–100 times that of a pristine photodetector, which is sufficient to be detected in experiments. Moreover, due to strong spin–orbit interactions, the Bi2C photodetector can produce very high spin polarization, even 100% full spin polarization, and pure spin current at a specific incident angle and photon energy, for example in the Bi1-vacancy Bi2C photodetector. In addition, the photon energy of incident light can regulate the produced spin photocurrent, which shows considerable anisotropy. Our results highlight the potential of the Bi2C photodetector as a versatile device in optoelectronics and spintronics applications. [ABSTRACT FROM AUTHOR]

Herein, a digital–analog hybrid resistive random‐access memory (RRAM) is prepared by integrating the structurally similar SiNx‐based digital‐type RRAM with analog‐type RRAM by heterogeneous integration method. The Pt/SiNx/Ta/Ru is a digital RRAM due to the formation and breakage of the internal silicon dangling bonds conductive filaments, and the TiN/SiNx/Ta/Ru structure is an analog RRAM due to the traps‐filled limit region of the space‐charge limited current. The heterogeneously integrated digital RRAM has good cycling stability and endurance characteristics, and the heterogeneously integrated analog RRAM has high linearity and multistate counting characteristics. This heterogeneous integration approach is useful for the implementation of hybrid digital–analog RRAM. [ABSTRACT FROM AUTHOR]

The photogalvanic effects (PGEs) in low-dimensional devices have attracted great interests recently. Herein, based on non-equilibrium Green's function combined with density functional theory, we investigated spin-dependent PGE phenomena in the BiC photodetector with the linearly polarized light and zero bias. Due to the presence of strong spin–orbit interaction (SOI) and C 3 v symmetry for the BiC monolayer, the armchair and zigzag BiC photodetectors can produce robust spin-dependent PGEs which possess the cos(2 θ) and sin(2 θ) relations on the photon energies, respectively. Especially, the pristine armchair and armchair Bi-vacancy BiC photodetectors can produce fully spin polarization, and pure spin current was found in the pristine armchair and zigzag BiC photodetector, respectively. Furthermore, after introducing the Bi-vacancy, C-vacancy, Bi-doping and C-doping respectively, the BiC photodetector can produce higher spin-dependent PGEs for their C s symmetry. Additionally, the behaviors of spin-dependent photoresponse are highly anisotropic which can be tuned by the photon energy. This work suggested great potential applications of the BiC monolayer on PGE-driven photodetectors in low energy-consumption optoelectronics and spintronic devices. [ABSTRACT FROM AUTHOR]

Herein, the effect of temperature on the switching characteristics and the conduction mechanism of the Ti/SiNx/Pt resistive random access memory device is investigated. The switching behavior of the device is investigated by comparing the I–V curves of the device in the temperature range of RT‐653 K. The temperature dependence of the current and the conduction mechanism of the device within RT‐463 K is investigated. It is found that the device exhibits good bipolar switching behavior in the temperature range of RT‐463 K, and the low resistance state (LRS) current and high resistance state (HRS) current show an increasing and then decreasing trend with increasing temperature. There is a stronger temperature dependence of the LRS current and the conduction mechanism from ohmic conduction to Schottky emission under LRS, which is attributed to the involvement of the reactive electrode Ti in the reaction at a certain temperature and the generation of a TiNx layer. Based on the above phenomenon, it is believed that not only the temperature affects the reliability of the device, but also the influence of reactive electrodes cannot be ignored. This article provides a reference for further preparation of SiNx‐based resistive random access memory devices with higher reliability and wider temperature usage range. [ABSTRACT FROM AUTHOR]

This Letter is about the role of the bottom electrode in the resistive switching of SiNx-based resistive random-access memory. Titanium nitride (TiN) and platinum (Pt) are used as bottom electrodes to fabricate devices whose I–V characteristics are compared. The devices with Pt as the bottom electrode have digital resistive switching behavior with a main memory window. However, the devices with TiN as the bottom electrode provide an analog resistive switching with the gradual operation. We propose that this switching difference is due to the different work functions of the top and bottom electrodes and the nitrogen-rich layer formed at the SiNx/TiN interface. The work function of the bottom electrode is larger than the top electrode in the device with Pt electrodes, which are considered non-reactive. However, the difference in the work functions between the bottom and top electrodes is not much for the device with a TiN electrode. As the nitrogen-rich layer formed at the SiNx/TiN interface has nitrogen accommodation ability, the nitrogen ions are more likely to drift to the bottom electrode, and resistive switching changes from digital to analog for the device with TiN electrodes. [ABSTRACT FROM AUTHOR]

In this Letter, a Pt/SiNx/TiN/Ta resistive random access memory (RRAM) is proposed, which has low switching voltage, uniform resistance distribution, excellent cycle-to-cycle stability, and excellent nonvolatile performance. As an insertion layer, TiN prevents excessive absorption of nitrogen ions by a Ta electrode and avoids the formation of the unstable metal–semiconductor interface, which significantly reduces cycle-to-cycle variability of SiNx-based RRAM. Due to high conductivity, the TiN layer has a small voltage divider effect when voltage was applied, which helps to achieve low power consumption characteristics. This paper provides a direction for improving performance of nitride-based RRAM, which is useful for further development of highly reliable RRAM. [ABSTRACT FROM AUTHOR]

This article presents an analysis of the effect of the Ta‐doping position on the performance of SiNx‐based resistive random access memories by comparing the electrical properties and conduction mechanisms of the devices. The electrical test results show that when the doping position moves down in the resistive switching (RS) layer, the resistance window of the device increases during the resistive switch process. However, the consistency of the parameter distribution decreases. The conduction mechanism of all Ta‐doped devices behaves as space charge limited current. According to the analysis of the RS model of the device, Ta in the RS layer connects and disconnects with the localized conductive filaments. The adjustment ability of the doping layer on the conductive channel and the reduction of the device stability when the doping position moves up are proposed. Proper Ta doping in the middle of the RS layer of the device allows the device to obtain a large resistance window with relatively stable characteristics. [ABSTRACT FROM AUTHOR]