C. J. Muller

Microfabrication of a Mechanically Controllable Break Junction in Silicon

We present a detailed description of the fabrication and operation at room temperature of a novel type of tunnel displacement transducer. Instead of a feedback system it relies on a large reduction factor assuring an inherently stable device. Stability measurements in the tunnel regime infer an electrode stability within 3 pm in a 1 kHz bandwidth. In the contact regime the conductance takes on a discrete number of values when the constriction is reduced atom by atom. This reflects the conduction through discrete channels.

The Electrical Measurement of Molecular Junctions

ABSTRACT: We present the investigation of the electrical transport of metal/(organic molecule or monolayer)/metal junctions. Utilizing a novel mechanically controllable break junction to form a statically stable system, we have self‐assembled molecules of benzene‐ 1,4‐dithiol onto two facing gold electrodes allowing for direct observation of charge transport through the molecules. Current‐voltage I(V) measurements provides a quantitative measure of the conductance of a junction containing a single molecule. We have also created a technique to form well‐defined, stable, and reproducible metallic contacts to a self‐assembled monolayer of 4‐thioacetylbiphenyl with nanoscale area. Electronic transport measurements show a prominent rectifying behavior arising from the asymmetry of the molecular heterostructure. Variable‐temperature measurements reveal the dominant transport mechanisms, such as thermionic emission for the Ti‐organic system. These techniques demonstrate the capability of electrically characterizing and engineering conductive molecular systems for future potential device applications.

Atomic probes: A search for conduction through a single molecule

We present a novel approach in an effort to perform electrical measurements at the level of a single molecule. A mechanical controllable break junction is utilized in combination with a molecular deposition technique in fluid to obtain the system: metal-molecule-metal. The I - V curve of this system shows pronounced features over a large voltage scale.

Molecular scale electronics: syntheses and testing

This paper describes four significant breakthroughs in the syntheses and testing of molecular scale electronic devices. The 16-mer of oligo(2-dodecylphenylene ethynylene) was prepared on Merrifields resin using the iterative divergent/convergent approach which significantly streamlines the preparation of this molecular scale wire. The formation of self-assembled monolayers and multilayers on gold surfaces of rigid rod conjugated oligomers that have thiol, -dithiol, thioacetyl, or -dithioacetyl end groups have been studied. The direct observation of charge transport through molecules of benzene-1, 4-dithiol, which have been self-assembled onto two facing gold electrodes, has been achieved. Finally, we report initial studies into what effect varying the molecular alligator clip has on the molecule scale wires conductivity.

Recent Advances in Molecular Scale Electronics

ABSTRACT: This paper describes four significant breakthroughs in the syntheses and testing of molecular scale electronic devices. The 16‐mer of oligo(2‐dodecylphenylene ethynylene) was prepared on Merrifields resin using the iterative divergent/convergent approach which significantly streamlines the preparation of this molecular scale wire. The formation of self‐assembled monolayers (SAMs) and multilayers on gold surfaces of rigid rod conjugated oligomers that have thiol, α,ω‐dithiol, thioacetyl, or α,ω‐dithioacetyl end groups have been studied. The direct observation of charge transport through molecules of benzene‐1,4‐dithiol, which have been self‐assembled onto two facing gold electrodes, has been achieved. Finally, we are reporting initial studies into what effect varying the molecular alligator clip has on the molecular scale wires conductivity.

There Is Plenty of Room Between Two Atom Contacts

The ability to manipulate matter atom by atom offers possibilities for new electronic devices and for studying new physical phenomena. In their Perspective, Muller and Reed discuss recent experiments in which current flows between contacts made from individual atoms. Such structures may be applicable in new sensor technologies.