van der Waals (vdW) heterogeneous integration and doping engineering have emerged as crucial factors in advancing the development of functional device systems. This work presents a fully vertical 2D/3D vdW stacking p-MoxRe1-xS2/GaN (x = 0.10 +/- 0.02) heterojunction photodetector, integrating multiple strategies for enhanced performance, such as mixed-dimensional stacking, p-type doping, vertical device design, and type-II band alignment. By integrating horizontal, vertical, and quasi-vertical devices on a Free-standing (FS)-GaN substrate, the vertical p-MoxRe1-xS2/GaN device demonstrates superior performance, including high I-light/I-dark ratio (1.48 x 10(6)), large Responsivity (888.69 AW(-1)), high specific detectivity (D*) (6.13 x 10(14) Jones), and fast response speed (rise/decay time of 181 ms/259 ms). Moreover, the spectral response encompasses the ultraviolet (UV), visible, and near-infrared (NIR) regions through energy band integration and bandgap modulation. This design surpasses previous devices, highlighting the potential of highly sensitive and micro-integrated optoelectronic devices enabled by vertical vdW heterogeneous integration.

In this study, a gallium nitride (GaN) substrate and its 15 μm epitaxial layer were entirely grown using hydride vapor phase epitaxy (HVPE). To enhance the breakdown voltage (VBR) of vertical GaN-on-GaN Schottky Barrier Diodes (SBDs), a dual ion co-implantation of carbon and helium was used to create the edge termination. The resulting devices exhibited low turn-on voltage of 0.55 V, high Ion/Ioff of approximately 109, and low specific on-resistance of 1.93 mΩ·cm2. With the ion implantation edge termination, the devices achieved a maximum VBR of 1575 V, with an average improvement of 126%. These devices demonstrated a high figure of merit (FOM) of 1.28 GW/cm2 and showed excellent reliability during pulse stress testing.

AbstractThe utilization of alloyed 2D transition metal dichalcogenides (TMDs) has become a pivotal approach for addressing challenges in material applications. The judicious selection of dopant constituents offers a potent means to finely modulate the materials' bandgap, consequently broadening the potential applications of 2D materials. In the context of an investigation, Mo1−x−yRexWyS2 is successfully synthesized using chemical vapor deposition. With a bandgap of 1.33 eV, this material exhibits promising prospects for application in the realm of optoelectronics. This advancement enables the fabrication of the Mo1−x−yRexWyS2 photodetector. The rigorous testing and analysis of photoelectric performance reveal significant improvements in both responsivity and response speed compared to analogous detectors. This accomplishment not only furnishes a novel paradigm for the advancement of photodetectors but also contributes fresh insights to the domain of alloyed 2D TMDs.

The main challenges in current vertical GaN diodes involve electric field crowding effects and ohmic contacts on the nitrogen face (N-Face). Extensive prior research has been conducted in these areas. In this study, we introduced a novel dual-ion (carbon and helium) co-implantation edge termination (ET), aiming to enhance the breakdown voltage $(V_{\text{BR}})$ capability of vertical GaN Schottky barrier diodes (SBDs). Furthermore, atomic layer deposition (ALD) was applied on the N-face to deposit a 1.2 nm aluminum oxide $(\text{AlO}_{x})$ layer, effectively reducing the contact resistance of the ohmic contacts $(\rho_{\mathrm{c}})$ . The fabricated devices exhibit a low turn-on voltage $V_{\text{on}}$ of 0.56 V and a high $I_{\text{on}}/I_{\text{off}}$ of $\sim 10^{9}$ . The introduction of $\text{AlO}_{x}$ mitigates the Fermi-level pinning effect (FLP), reducing the device resistance $R_{\text{on},\text{sp}}$ from 3.01 $\mathrm{m}\Omega\cdot \text{cm}^{2}$ to 1.34 $\mathrm{m}\Omega\cdot \text{cm}^{2}$ . Moreover, the dual-ion co-implantation ET enables the devices to achieve a maximum $V$ BR of 1410 V, resulting in a high figure of merit (FOM) of 1.48 GW/cm 2 .

In this work, vertical gallium nitride (GaN) trench Junction Barrier Schottky (JBS) diodes fabricated with a novelty slanted p-GaN sidewall on a 2-inch free-standing GaN (FS-GaN) substrate were demonstrated. The slanted sidewall on edge of devices was conducted to suppress the peak of electric field distributions at high voltage. By realizing an off-state breakdown voltage $V_{BR}$ of 2 kV and an on-state resistance $R_{on}$ of 1.34 $\text{m}\Omega \bullet $ cm2, the devices fabricated in this work achieved the highest power device figure-of-merit $V_{BR}^{2}/R_{on}$ of 3.0 GW/cm2 in the reported vertical GaN JBS diodes which showed great potential in high voltage applications.

Silicon (Si) material is the mainstream semiconductor material for a long time because of its relatively excellent hightemperature resistance, radiation resistance, low price, and huge reserves. However, with the rapid development of power electronics technology, the development of technology has reached a bottleneck period, and Moore's law has gradually failed. The existing silicon-based semiconductor devices are close to the theoretical limit of Si materials and can no longer meet the performance requirements of future power devices. However, the cost of transistors is constantly rising, and the performance improvement is slow, gradually moving towards the post-Moore era. To further improve the performance of the device, it is necessary to seek new technologies or new materials to support the continuous development of power devices, and the core of the progress of power semiconductor devices is the development of semiconductor materials. As the third generation of wide band gap semiconductors, gallium nitride (GaN) has been superior to Si in terms of material properties. GaN has the advantages of a wide band gap, high critical field strength, high electron saturation velocity, high conductivity, high-temperature resistance, and high voltage resistance. Compared with traditional Si-based power devices, it not only has higher breakdown voltage, low on-resistance, high electron mobility and good thermal conductivity, but also has smaller device volume and better heat dissipation performance under the same performance, which greatly reduces power consumption and achieves the effect of energy saving and emission reduction. The cost of early GaN single crystal preparation and epitaxial growth is beyond reach. However, with the mature development of growth technology, not only the cost of GaN single crystal substrate and its epitaxial growth is decreasing, but also the quality is gradually increasing, which lays a solid foundation for the wide application of GaN power devices in the future. This paper lists the main physical parameters of GaN and other semiconductor materials, the preparation of GaN single crystal, and the main methods of its epitaxy growth, and describes the advantages of GaN power devices in the current environment. For the device structure, the problems of the lateral device and the advantages of the vertical device are listed, and why the vertical device can become the mainstream structure of future power devices is explained. On this basis, the structure, working principle, research progress, and existing problems of vertical current aperture GaN transistor (CAVET), trench GaN MOSFET, vertical trench MOSFET based on in-situ oxidation GaN interlayer (GaN OG-FET), and vertical GaN fin field effect transistor (GaN FinFET) are introduced in detail. The performance parameters of vertical GaN power transistors mentioned in this paper are summarized in tables according to device types and time sequence, and the general direction of the development of GaN power transistors in the future is proposed. For integrated circuit systems, the special requirements and key technologies of GaN power devices in driver chips are summarized. Finally, for the current market environment, listing the vertical GaN power transistor in the medium and low voltage range is a more popular and promising application scenario.

Al1−x In x N, a III-nitride semiconductor material, is currently of great research interest due to its remarkable physical properties and chemical stability. When the Al and In compositions are tuned, its band-gap energy varies from 0.7 eV to 6.2 eV, which shows great potential for application in photodetectors. Here, we report the fabrication and performance evaluation of integrated Al1−x In x N on a free-standing GaN substrate through direct radio-frequency magnetron sputtering. The optical properties of Al1−x In x N will be enhanced by the polarization effect of a heterostructure composed of Al1−x In x N and other III-nitride materials. An Al1−x In x N/GaN visible-light photodetector was prepared by semiconductor fabrication technologies such as lithography and metal deposition. The highest photoresponsivity achieved was 1.52 A⋅W−1 under 365 nm wavelength illumination and the photodetector was determined to have the composition Al0.75In0.25N/GaN. A rise time of 0.55 s was observed after transient analysis of the device. The prepared Al1−x In x N visible-light photodetector had a low dark current, high photoresponsivity and fast response speed. By promoting a low-cost, simple fabrication method, this study expands the application of ternary alloy Al1−x In x N visible-light photodetectors in optical communication.

This study investigates the effect of helium-implanted edge termination (ET) on GaN-on-GaN Schottky barrier diode (SBD) temperature sensors. Devices with and without ET of three different diameters are fabricated and characterized from 298 to 473 K. Based on the conventional calculation method, the results show that the sensitivity (Sm) of the device with ET is lower than that of the device without ET at the same given current with the same anode area. Technology Computer Aided Design (TCAD) simulation reveals that ET can restrict the current to a smaller area, resulting in a larger actual current density (JA) for devices with ET. After correcting (JA) in the sensitivity calculation, the two types of devices exhibit the same corrected sensitivity (Sc) values, which also follow the fundamental linearity theory of sensitivity versus the natural logarithm of JA with high sensitivity corresponding to the lower current density. This pseudo-degradation phenomenon of sensitivity after the ET process can serve as a reference for in situ temperature monitoring in the gallium nitride (GaN)-based integrated-circuit design.

Off-line gamma-ray spectrometry was used to accurately measure the Cumulative fission product yields (CFPYs) of fission products in the 235U (n, f) reaction induced by 2.8 MeV neutrons. The 2.8 MeV quasi-monoenergetic neutron beam was produced by the CPNG-600 Cockcroft Walton accelerator at the China Institute of Atomic Energy （CIAE）and the gamma spectra were measured by the HPGe γ-ray Spectrometer. After fully considering and revising the sources of uncertainty, high-precision CFPYs of 4 fission products were obtained. This study has important applications in reactor design and operation and is conducive to the establishment of an evaluated nuclear database.

抽油机是油井工程中最为重要的设备之一,对于油井工程建设至关重要.我国的部分油田由于地势比较低洼,地下水位较高,为了保障抽油机设备的正常运行,需要对抽油机进行基础加高作业.针对大型抽油机采用基础倒置施工技术可以有效提高壁板顶面的平滑度,确保安装的精确性,并且实现大型抽油机设备的就近安装.本文通过介绍了大型抽油机基础倒置施工技术的要点,为相关工作的开展提供参考.

苏里格气田标准化集气站主要包括单井集气、气液分离、闪蒸放空、增压外输等环节,天然气是处理集输的主要产品,而气田产出液则是另一大主体,它的集输处理同等关键,直接制约着天然气的生产.通过集气站自动化设备、可编程逻辑控制器及上位机人机界面等过程有机结合,研究设计一系列自动化集输、联锁控制功能,实现产出液自动化集输处理,解决气田产出液排液、存储、输送、拉运等各方面的安全生产、高效操作等问题.

CS3000 DCS控制系统中,温压补偿算法模块是针对理想气体和压差式流量计而设计的,不适用于过热蒸汽流量的补偿计算.文中提出利用密度内插法对过热蒸汽进行温压补偿,并利用CS3000控制系统中顺序控制功能模块SFC实现该补偿算法,为系统组态提供过热蒸汽温压补偿算法模块.现场监测结果表明,补偿后蒸汽流量值与设计消耗流量值的相对误差在2.0％左右,满足化工装置蒸汽流量测量需要.

从焊接工艺的概念入手,阐述了编制焊接工艺评定报告中常见的质量问题以及问题产生的原因和危害.针对焊接工艺评定报告的审查内容、覆盖范围、焊接人员对报告的熟悉程度和现场执行及监理的管控情况,结合实际工作经验,提出了焊接工艺的监督方法,以规范施工、监理单位的质量行为,提高焊接工艺质量.

为提高对无损检测工作的问题发现能力及监管工作效率,结合多年从事专业检测及监督工作经验,提出一些便于操作、针对性强的监管措施.在简要介绍无损检测工作一般流程的基础上,论述了检测标准用错、标准适用范围不明、检测过程资料不全、无损检测部分漏检、检测结果虚假、缺陷检出率低等无损检测工作中较常出现的一些问题,并给出纠正建议.

由于输送天然气水露点较高,达到了生成天然气水合物的条件,致使天然气管道站场生产运行过程中发生了冰堵现象,严重影响管道的安全运行.通过分析天然气水合物的形成,给出了天然气管道运行过程中冰堵的预防措施及其实际应用技术条件.根据天然气水合物的生成机理,得出分输站场冰堵的解堵过程.通过典型案例分析,进一步说明天然气管道冰堵的发生过程和解堵措施的应用,为天然气管道运行中冰堵现象的预防和解除提供理论指导和技术支持.

油气田地面工程建设规模不断扩大,工程技术风险、质量风险日益突出,给质量监督管理工作带来了新的困难和问题.通过“一体两翼”监督模式在工作中的实际应用,阐述了如何应用“一体两翼”模式,不断提高建设工程质量,确保地面建设工程本质安全.

针对油田矿区服务质量监督制度、方法、措施存在的滞后状况,以现代化先进服务理念为指导,加大服务质量监督力度为对策,通过改进服务监督方法,转变服务作风,提高了矿区整体服务水平的针对性、科学性和实效性.