Photoassisted Formation of an Atomic Switch

Abstract

communications Figure 5. SEM image of the Ag-bridged electrode with a 20-nm gap. Observations were carried out after removing the PTCDI thin layer with chloroform. There are some Ag deposits observed on the Pt and Ag 2 S/Ag electrodes, which seems to have emerged during the switching experiment.

Ag2S atomic switch-based ‘tug of war’ for decision making

“…18 This limitation is for instance utilized in volatile and nonvolatile selective switching of photo-assisted atomic switches. 19,20 Decision making based on these atomic switches was very recently proposed theoretically by Kim et al 21 In this study, we extend the function of atomic switches so that they can achieve the 'tug of war' operation. In conventional gap-type atomic switches, growth and shrinkage of a metal filament between two electrodes, a solid electrolyte electrode such as α-Ag 2+δ S and a counter metal electrode, are controlled, see Fig.…”

Advanced Photoassisted Atomic Switches Produced Using ITO Nanowire Electrodes and Molten Photoconductive Organic Semiconductors

“…Atomic switches produced with a metal/open‐gap/Ag 2 S/Ag structure have attracted much attention for use in ultra‐high‐density nonvolatile memory devices that consume low amounts of power, because the atomic switching is performed through the formation and shrinkage of Ag conductive nanowire bridges between 1 nm‐gap electrodes . Making the gap wider and filling the gap with a functional materials such as photoconductive organic materials is a fascinating concept for achieving a functional atomic‐switch device since external fields such as electric and magnetic fields could be applied to the gap, which also plays an important role in forming Ag conductive bridges . We previously used N , N ′‐diheptylperylenetetracarboxylicdiimide (PTCDI), a photoconductive organic material, to demonstrate just the bridging process of a photoassisted atomic switch (PAS) .…”

“…Making the gap wider and filling the gap with a functional materials such as photoconductive organic materials is a fascinating concept for achieving a functional atomic‐switch device since external fields such as electric and magnetic fields could be applied to the gap, which also plays an important role in forming Ag conductive bridges . We previously used N , N ′‐diheptylperylenetetracarboxylicdiimide (PTCDI), a photoconductive organic material, to demonstrate just the bridging process of a photoassisted atomic switch (PAS) . After bridging of the Ag wire, the junction worked as a general atomic switch.…”

“…A photoconductive organic material was applied to the electron transport layer between two electrodes in previous PAS devices; therefore, the proposed PAS does not require the short gap distance of about 1 nm, which is required for conventional atomic switches . Silver sulfide (Ag 2 S), a mixed ionic and electronic conductor, is used as the material for growing Ag conductive bridge as follows: Irradiating the photoconductive material with light and applying a positive bias to the Ag 2 S/Ag electrode, on the one hand, can cause photocurrent to flow between the counter and Ag 2 S/Ag electrodes, enabling an Ag conductive bridge to grow and cross the gap.…”

“…Applying positive bias to an Ag 2 S/Ag electrode in the dark, on the other hand, does not cause an extension of an Ag conductive bridge because of the lack of photocurrent. Once the bridges are formed, the switch works as a conventional atomic switch by alternating the polarity of the applied bias voltage . Although PAS devices are promising for achieving functional atomic switches, the use of the solid photoconductive material and the lithographically patterned electrode to form a ≈100 nm Ag conductive bridge may degrade the PAS because it is difficult to compensate for the formation of voids during the shrinking of Ag bridges.…”