Plasmon-induced nanoscale quantised conductance filaments

Abstract

Plasmon-induced phenomena have recently attracted considerable attention. At the same time, relatively little research has been conducted on electrochemistry mediated by plasmon excitations. Here we report plasmon-induced formation of nanoscale quantized conductance filaments within metal-insulator-metal heterostructures. Plasmon-enhanced electromagnetic fields in an array of gold nanodots provide a straightforward means of forming conductive CrOx bridges across a thin native chromium oxide barrier between the nanodots and an underlying metallic Cr layer. The existence of these nanoscale conducting filaments is verified by transmission electron microscopy and contact resistance measurements. Their conductance was interrogated optically, revealing quantised relative transmission of light through the heterostructures across a wavelength range of 1–12 μm. Such plasmon-induced electrochemical processes open up new possibilities for the development of scalable devices governed by light.

Controlled Construction of Atomic Point Contact with 16 Quantized Conductance States in Oxide Resistive Switching Memory

“…On the basis of the filamentary conduction theory, , plural and percolative CFs are usually formed by random mobile ion migration along the grain boundaries in polycrystalline oxide films (Figure a). The stochastic annihilation and regeneration of the multiple CFs will result in severe fluctuation of the programming voltages and ON/OFF resistances, as well as the deterioration of device retention and endurance performance, , which appear as critical obstacles that hinder the resistive switching memory for practical applications. The highly leaky pathways, associated with the abundant numbers of crystalline defects, would also lead to a large OFF state current and power consumption of the devices. , To restrain the random formation and evolution of the conductive filaments, herein we have deliberately utilized a scanning probe microscope as a pretreatment toolkit to regulate the ion and electric field distribution across the oxide switching layers, with the aim of producing single CF and APC in memory devices.…”

“…For instance, ion implantation or doping has been widely employed to regulate the concentration and distribution of mobile ions in the switching layer, − while the electrode engineering strategy with embedded nanoparticles has been developed to confine the directional motion of mobile ions under the locally enhanced electric field. , A scanning probe microscope (SPM) provides a useful toolkit to correlate the sample local conductivity with ion migration and surface morphology in resistive switching memories . Taking its ability of nanolithography patterning via local ion manipulation and surface electrochemistry into account, − the conductive mode of the SPM technique (e.g., conductive-atomic force microscope) is also capable of accurately fabricating artificial nanostructure and electronic devices. , By direction of the oriented migration of mobile ions with tip-enhanced local electric field, the scanning probe microscope may facilitate the controlled formation and evolution of conductive filaments, thereby significantly improving the overall performance of the memory devices. − …”

Measurements of electrically tunable refractive index of MoS2 monolayer and its usage in optical modulators

“…7,10 This excitonic absorption is larger than the broadband absorption of graphene. 14 Despite the fact that the optical absorption of MoS 2 monolayers in the visible range is relatively large compared to other 2D materials, 15 its absolute value is still rather small. Therefore, in order to utilise MoS 2 monolayers in optical devices it is essential to create light trapping nanostructures which would significantly enhance light interaction with the 2D semiconductor atomic layer.…”