Current Switching Coupled to Molecular Spin‐States in Large‐Area Junctions

Abstract

The fabrication of large-area vertical junctions with a molecular spin-crossover complex displaying concerted changes of spin degrees of freedom and charge-transport properties is reported. Fabricated devices allow spin-state switching in the spin-crossover layer to be triggered and probed by optical means, while detecting associated changes in electrical resistance in the junctions.

Spin Crossover Nanomaterials: From Fundamental Concepts to Devices

“…While the mechanistic details remain mostly uncovered, from the inversion of the conductance (i.e., a more conducting HS state) it is clear that the charge transport mechanism in these junctions is indeed not related to the bulk properties. Vertical, multilayer tunneling junctions with thin films of the [Fe(H 2 B(pz) 2 ) 2 (phen)] spin crossover complex sandwiched between ITO and Al electrodes were also reported (Figure d) . A key interest of these large‐area devices is that they provide means to trigger and probe the spin‐state switching in the SCO layer by conventional optical methods, while simultaneously detecting the associated electrical resistance changes in the junctions.…”

“…d) Large area (3 mm 2 ) vertical tunneling junction made of a 10 nm thin film of the SCO complex [Fe(H 2 B(pz) 2 ) 2 (phen)] between ITO and Al electrodes: SEM image of the junction cross‐section and variation of the junction resistance due to the LIESST effect. Reproduced with permission . Copyright 2016, Wiley‐VCH.…”

“…This problem will be addressed in the second part of this review, while the third part will be devoted to examples of successful integration of SCO nanomaterials into devices. The most advanced and most straightforward device concepts use photonic principles—mainly for sensing purposes, but recent results revealed promising perspectives also for applications in electronic junctions and mechanical actuators . At this point it must be noted that, in strong connection with the development of SCO nanomaterials, there has been a significant experimental and theoretical progress also in exploring the properties of single isolated SCO molecules on surfaces with the primary aim to use them in single molecule electronic devices.…”

Engineering On‐Surface Spin Crossover: Spin‐State Switching in a Self‐Assembled Film of Vacuum‐Sublimable Functional Molecule

“…Metal–organic spin‐crossover (SCO) complexes that are capable of undergoing switching between low‐spin (LS) and high‐spin (HS) states as a function of temperature, light, pressure, and electric field are suitable candidates to fabricate room‐temperature‐operable molecular electronic/spintronics architectures . Relentless efforts have been made to study spin‐state switching characteristics of SCO complexes on different surfaces to harness the device utility of SCO entities.…”

Electron Transfer in the Cs⊂{Mn4Fe4} Cubic Switch: A Soluble Molecular Model of the MnFe Prussian‐Blue Analogues

“…[1,2] For example, the deposition of these systems onto substrates [3,4] or their integration into advanced hybrid materials [5][6][7] could lead to original moleculebased nanodevices. [8][9][10] Molecules exhibiting reversible metal-to-metal electron transfer (ET) are particularly attractive because they are able to change their optical, magnetic, or dielectric properties under the application of different stimuli such as irradiation, temperature, pressure change, or voltage. Cyanide coordination chemistry provides many examples of such switchable systems.…”