AlN/GaN double-barrier resonant tunneling diodes RTDs were grown by metal-organic chemical vapor deposition on sapphire. RTDs were fabricated via standard processing steps. RTDs demonstrate a clear negative differential resistance NDR at room temperature RT . The NDR was observed around 4.7 V with a peak current density of 59 kA /cm2 and a peak-to-valley ratio of 1.6 at RT. Dislocation-free mat...

A terahertz quantum cascade laser is presented in which selectively placed pure AlAs barriers are used to reduce parasitic leakage currents to the conduction band continuum. The design is demonstrated to have improved temperature performance over a regrowth of the current Tmax 200 K record holder (181 K vs. 175 K). Strangely, it fails to lase below 70 K, which we attribute to negative different...

We discuss several proposed explanations for the switching and negative differential resistance (NDR) behavior seen in some molecular junctions. Several theoretical models are discussed, and we present results of electronic structure calculations on a series of substituted oligo(phenylene ethynylene) molecules. It is shown that a previously proposed polaron model is successful in predicting NDR...

Combining insights from quantum chemistry calculations with master equations, we discuss a mechanism for negative differential resistance (NDR) in molecular junctions, operated in the regime of weak tunnel coupling. The NDR originates from an interplay of orbital spatial asymmetry and strong electron-electron interaction, which causes the molecule to become trapped in a nonconducting state abov...

In this paper, we propose a new heterostructure dual material gate junctionless field-effect transistor (H-DMG-JLFET), with negative differential resistance (NDR) characteristic. The drain and channel material are silicon and source material is germanium. The gate electrode near the source is larger. A dual gate material technique is used to achieve upward band bending in order to access n-i-p-...

An electrically bistable device has been fabricated based on poly(N-vinylcarbazole) (PVK)-silver sulfide (Ag2S) composite films using a simple spin-coating method. Current-voltage (I-V) characteristics of the as-fabricated devices exhibit a typical electrical bistability and negative differential resistance (NDR) effect. The NDR effect can be tuned by varying the positive charging voltage and t...

The transport characterization of self-assembled monolayers (SAMs) based on the closed and open-shell forms of a fully conjugated polychlorotrimethylphenyl (PTM) derivative hybridized with the gold substrate reveals that both systems exhibit negative differential resistance (NDR) in their I-V curves which was attributed to similar resonant tunnelling with unoccupied molecular orbitals. This wor...

106204-9494 IJECS-IJENS © August 2010 IJENS I J E N S  Abstract— Superlattice emitter resonant tunneling bipolar transistor (SE-RTBT) is facing problem due to thermal transfer of electrons over barrier which causes diminishing negative differential resistance (NDR) effect. Therefore resonant tunneling diode (RTD) with higher quasibound state energy causes transfer of electrons by RT effect ins...

We investigate the atomic-scale tunneling characteristics of bilayer graphene on silicon carbide using the scanning tunneling microscopy. The high-resolution tunneling spectroscopy reveals an unexpected negative differential resistance (NDR) at the Dirac energy, which spatially varies within the single unit cell of bilayer graphene. The origin of NDR is explained by two near-gap van Hove singul...

We investigate the spin transport properties of iron-phthalocyanine (FePc) molecule sandwiched between two N-doped graphene nanoribbons (GNRs) based on the density functional theory and nonequilibrium Green's function methods. Our calculated results clearly reveal that the FePc molecular junction has high spin-filter efficiency as well as negative differential resistance (NDR). The zero-bias co...