Achieved negative differential resistance behavior of Si/B-substituted into a C6 chain sandwiched between capped carbon nanotube junctions

Multi negative differential resistance (NDR) with large peak to valley ratio (PVR) and rectifying actions were observed for a CNT|C–(B–C)2–C|CNT molecular device.

EFFECT OF ASYMMETRIC LATERAL LINKING GROUPS ON THE ELECTRONIC TRANSPORT IN MOLECULAR DEVICE

The effect of asymmetric lateral linking groups on the electronic transport is investigated in the biphenyl molecule-based device with gold electrodes with the framework of density functional theory and nonequilibrium Green’s function. The asymmetric lateral linking groups reduce the currents of molecular junctions, and result in the reverse rectifying behavior. The devices with asymmetric lateral linking groups –SH and –SCH3 have maximum rectifying ratios, while the asymmetric lateral linking group –SH and –NH2 cause minimum rectifying ratios. The calculated results suggest that the asymmetric lateral linking group induces the reduced coupling between molecule and right electrode, asymmetric distribution of frontier molecular orbital and asymmetric evolution of the molecular orbital eigenenergies, accounting for the rectifying behavior.

Molecular coupling competing with defects within insulator of the magnetic tunnel junction-based molecular spintronics devices

Nearly 70 years old dream of incorporating molecule as the device element is still challenged by competing defects in almost every experimentally tested molecular device approach. This paper focuses on the magnetic tunnel junction (MTJ) based molecular spintronics device (MTJMSD) method. An MTJMSD utilizes a tunnel barrier to ensure a robust and mass-producible physical gap between two ferromagnetic electrodes. MTJMSD approach may benefit from MTJ's industrial practices; however, the MTJMSD approach still needs to overcome additional challenges arising from the inclusion of magnetic molecules in conjunction with competing defects. Molecular device channels are covalently bonded between two ferromagnets across the insulating barrier. An insulating barrier may possess a variety of potential defects arising during the fabrication or operational phase. This paper describes an experimental and theoretical study of molecular coupling between ferromagnets in the presence of the competing coupling via an insulating tunnel barrier. We discuss the experimental observations of hillocks and pinhole-type defects producing inter-layer coupling that compete with molecular device elements. We performed theoretical simulations to encompass a wide range of competition between molecules and defects. Monte Carlo Simulation (MCS) was used for investigating the defect-induced inter-layer coupling on MTJMSD. Our research may help understand and design molecular spintronics devices utilizing various insulating spacers such as aluminum oxide (AlOx) and magnesium oxide (MgO) on a wide range of metal electrodes. This paper intends to provide practical insights for researchers intending to investigate the molecular device properties via the MTJMSD approach and do not have a background in magnetic tunnel junction fabrication.

Comparative Study of Symmetrical And Asymmetrical B40 Molecular Junctions

The quantum transport in symmetric and asymmetric borospherne based molecular junction with adenine has been probed. Adenine is a nucleobase of DNA among the four nucleobases of DNA, adenine is selected because of its excellent transport properties. The DFT-NEGF mathematical approach has been utilized. This was further used to calculate quantum transport parameters such as the I-V curve, transmission spectra, highest occupied molecular orbital (HOMO)- lowest occupied molecular orbital (LUMO) gap (HLG), differential conductance, and transmission pathways. From our research work we have noticed that both symmetric and asymmetric devices exhibit non-linear behavior thus leading to non-differential resistance (NDR). Alos symmetric B40 molecular device has reduced HLG in contrast to asymmetric B40 molecular device. This drop-in HLG is due to a reduction in electron density. A high rectification ratio for the devices is observed at 0.2V. Hence symmetric and asymmetric B40 molecular junction is the potential candidates that can be utilized in future nano-scale devices.

Elucidating Multiple Negative Differential Resistance and Rectification Ratio Through L-Aspartic Acid at Nanometre Scale Using Symmetrical Metal Electrodes

Protein-based electronics is one of the growing areas of bio-nanoelectronics, where novel electronic devices possessing distinctive properties, are being fabricated using specific proteins. Furthermore, if the bio-molecule is analysed amidst different electrodes, intriguing properties are elucidated. This research article investigates the electron transport properties of L-aspartic acid (i.e., L-amino acid) bound to symmetrical electrodes of gold, silver, copper, platinum and palladium employing NEGF-DFT approach using self-consistent function. The theoretical work function of different electrodes is calculated using local density approximation and generalized gradient approximation approach. The calculated work function correlates well with the hole tunnelling barrier and conductance of the molecular device, which further authenticate the coupling strength between molecule and electrode. Molecule under consideration also exhibits the multiple negative differential resistance and rectification ratio with all the different electrodes, due to its asymmetrical structure. The molecular device using platinum electrodes exhibits the highest peak to valley ratio of 1.38 and rectification ratio of 3.20, at finite bias. The switching characteristics of different molecular device are justified with detailed transmission spectra and MPSH. These results indicate that L-aspartic acid and similar biomolecule can be vital to the growth of Proteotronics.