Effects of molecular environments on the electrical switching with memory of nitro-containing OPEs

Abstract

An oligo͑phenylene ethynylene͒ ͑OPE͒ molecule with a nitro side group has exhibited electrical switching with memory and thus has potential for use in molecular electronic devices. However, different research groups have reported different electrical behaviors for this molecule. In addition to variations among test structures, differences in local molecular environments could be partially responsible for the differences in the reported results. Thus, we tested four variations of a nitro-OPE/ dodecanethiol monolayer in the same type of nanowell test device to study how the environment of the nitro-OPE affects the observed electrical behavior. We found that the density of the nitro-containing molecules in the device altered the observed electrical switching behavior. Further, we found a positive correlation between the disorder of the monolayer and the observed electrical switching behavior. This correlation is consistent with suggestions that nitro molecule switching may depend on a conformational change of the molecule, which may be possible only in a disordered monolayer.

First-principles determination of the effects of intermolecular interactions on the electronic transport through molecular monolayers

“…These experiments address monolayers of self-assembled molecules, where intermolecular interactions are present, rather than isolated molecules. 13,14 This is especially true for OPE thiols and derivatives such as the nitroOPE considered here, which assembles in highly ordered patterns with typical domains of about 100 Å. 15 Therefore, a two-dimensional ͑2D͒ model is more suitable for comparison to experimental settings rather than a 1D one, in the sense that they include the effect of a single molecule surrounded by neighboring ones.…”

Two‐Terminal Molecular Memory through Reversible Switching of Quantum Interference Features in Tunneling Junctions

“…Given sufficient trace/retrace stability, hysteresis is a form of two‐terminal bias switching, but to translate it into a memory effect, the state of a static, two‐terminal junction must be switched reversibly between at least two conductance states in operando. To characterize the memory effects of metal/SAM//EGaIn junctions, we performed write operations (W) by applying a −1.50 V bias, which puts the junction in the high‐conductance ON state, and erase operations (E) by applying 1.00 V, which puts it in the low‐conductance OFF state.…”

On-chip characterization of molecular electronic devices using CMOS

“…Such a hybrid design paradigm would be able to take advantage of the best that each technology has to offer [24,30]. Yet, most of the experimental research and development in this relatively new field has involved individual "test devices" that use processes that increase the ease and effectiveness of achieving and evaluating molecule-dependent transport [1][2][3][4][5][6]8,[11][12][13][14][16][17][18]20,21,[27][28][29], but in many cases disregard integration potential. Additionally, most of the device characterization that has been performed has been limited to individual external probing methods, rather than coherent characterization in a circuit environment.…”

“…Additionally, most of the device characterization that has been performed has been limited to individual external probing methods, rather than coherent characterization in a circuit environment. This is true even though the leading research in molecular electronics has shown that the devices are so environmentally sensitive that minor changes can drastically alter their electrical behaviors [4,8,18,23,26]. Thus, the development of CMOS compatible molecular electronic devices that can be characterized on-chip is essential to the realization of hybrid CMOS-molecular systems.…”