ISSN:
1573-7357
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract Single electron tunneling devices were made by combiningstandard electron beam lithography and the self-assembly ofchemically synthesized gold clusters. These clusters, withdiameters from 2 to 5 nm, were captured in a 5–10 nm gapbetween two gold electrodes. The gold particles as well as theelectrodes were covered with self-assembled monolayers (SAM)of organic molecules which served as tunnel barriers.Operating devices show a suppressed current due to the Coulombblockade of tunneling at room temperature. When cooled to4.2 K, a Coulomb staircase was observed. By applying a voltageto an oxidized aluminum gate beneath the electrodes and thetrapped gold cluster the current voltage characteristics weremodulated. Anomalous effects are observed such as constantcurrent plateaus whose positions are gate-voltage dependent.An electrodeposition method for gold has been used tofabricate gaps between electrodes smaller than 2 nm. A self-assembled monolayer was used successfully on the electrodes inorder to prevent the gold atoms from migrating on the surfacebetween the electrodes and thereby short-circuiting thejunction. The conductance of such a tunnel junction has beenmeasured and compared to the theory with good agreement. Fromthis comparison the capacitance of the junction was estimated,and we could use that value to calculate a rough estimation ofthe distance between the electrodes.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1004637932760
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