The elemental Nb is mainly investigated for its eminent superconducting properties. In contrary, we report of a relatively unexplored property, namely, its superior optoelectronic property in reduced dimension. We demonstrate here that nanostructured Nb thin films (NNFs), under optical illumination, behave as room temperature photo-switches and exhibit bolometric features below its superconducting critical temperature. Both photo-switch and superconducting bolometric behavior are monitored by its resistance change with light in visible and near infrared (NIR) wavelength range. Unlike the conventional photodetectors, the NNF devices switch to higher resistive states with light and the corresponding resistivity change is studied with thickness and grain size variations. At low temperature in its superconducting state, the light exposure shifts the superconducting transition towards lower temperature. The room temperature photon sensing nature of the NNF is explained by the photon assisted electron-phonon scattering mechanism while the low temperature light response is mainly related to the heat generation which essentially changes the effective temperature for the device and the device is capable of sensing a temperature difference of few tens of milli-kelvins. The observed photo-response on the transport properties of NNFs can be very important for future superconducting photon detectors, bolometers and phase slip based device applications.
Electroforming Free Controlled Bipolar Resistive Switching in Al/CoFe2O4/FTO device with Self-Compliance Effect
利用Al（铝）/CoFe 2 O 4/FTO（掺氟氧化锡）器件在纳米结构CoFe 2 O 4薄膜中观察到可控双极阻变（BRS）。所制造的器件示出了无电铸的均匀BRS，其具有两个清楚区分的且稳定的电阻状态，而没有任何顺从电流（CC）的施加，其中高电阻状态（HRS）和低电阻状态（LRS）的电阻比> 102。小的开关电压（< 1伏）和两种电阻状态下的较低电流证实了低功耗器件的制造。在LRS中，导电机制被发现是欧姆性质，而高电阻状态（HRS/OFF状态）是由空间电荷限制的导电机制，这表明存在的界面层与不完善的微观结构附近的顶部Al/CFO界面。该器件表现出非易失性行为，具有良好的耐久性能、可接受的电阻比、由于稳定的、较少随机的细丝形成/断裂而导致的均匀的电阻切换以及通过选择不同的停止电压对电阻切换性能的控制，这使得该器件适合于其在未来的非易失性电阻随机存取存储器（ReRAM）中的应用。
Optical imaging of strain-mediated phase coexistence during electrothermal switching in a Mott insulator
电阻开关-电流/电压引起的电阻变化-是忆阻器件的核心，在新兴的神经形态计算领域发挥着重要作用。本研究是关于莫特绝缘体中的电阻开关，其经历热驱动的金属到绝缘体的转变。两种不同的开关机制，这样的系统：电场驱动的电阻开关和磁阻开关。后者是由焦耳热引起的不稳定性引起的。在这里，我们提出了可视化的可逆电阻开关在平面V $_2$ O $_3$薄膜器件使用高分辨率宽场显微镜结合电输运测量。我们研究了V $_2$ O $_3$薄膜在Mott相变时的应变诱导自发相分离与晶格不稳定性的相互作用。显微照片显示形成了最小宽度为$\lesssim$ 500 nm的窄金属丝。虽然灯丝的形成和整体形状的电流-电压特性（IVC）是典型的击穿，我们也观察到非典型的影响，如倾斜的灯丝，灯丝分裂，和滞后IVC锯齿状跳跃在高电流在低电阻制度。我们能够重现实验结果的数值模型的基础上的二维电阻网络。该模型表明，在这种情况下，阻变确实是不均匀的，并且内在的异质性是造成非典型效应的原因。这种异质性的强烈影响的应变，从而建立一个开关动态和结构特性之间的联系。
High-Throughput Computational Discovery of Inverted Resistive Switching in Two-Dimensional Materials
Science, Mathematics and Technology (SMT) Cluster, Singapore University of Technology and Design（新加坡科技设计大学）；Institute of Advanced Intelligence and Computing (IAIC), Agency for Science, Technology and Research (A*STAR)（科学技术研究局）；School of Information Science and Technology, Northwest University（西北大学）；School of Physics and Optoelectronics, Xiangtan University（湘潭大学）；Institute of Brain-Inspired Intelligence, National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Physical Science Research Center, Nanjing University（南京大学）；Quantum Innovation Centre (Q. InC), Agency for Science Technology and Research (A*STAR)（科学技术研究局）；Department of Mechanical Engineering, National University of Singapore（新加坡国立大学）；Department of Materials Science and Engineering, National University of Singapore（新加坡国立大学）；Department of Electrical and Computer Engineering, National University of Singapore（新加坡国立大学）
