Volume 85, Issue 6, 15 March 1999
Index of content:
Gold cluster formation at the interface of a gold/Langmuir-Blodgett film/gold microsandwich resulting in Coulomb charging phenomena85(1999); http://dx.doi.org/10.1063/1.369691View Description Hide Description
Structural analysis of the cross section of gold/Langmuir-Blodgett (LB) polymer film/gold sandwich structures was performed using transmission electron microscopy(TEM), and the obtained results were complemented by electron transport investigations of the sandwich structures. The polymer film consisted of four to ten LB monolayers of a nonconducting polymer. TEM analysis of the sandwich cross section revealed a number of gold particles, 2–5 nm in size, formed during the fabrication process within the LB film close to the top electrode. Low temperature dc-transport measurements showed current-voltage characteristics with equidistant steps that are not expected if the polymer film is thought to form a single laterally extended tunneling barrier between the metal electrodes. This feature can be understood, however, on the basis of the Coulomb blockade model applied to cluster-like metallic inclusions acting as an island separated from both Auelectrodes by tunneling barriers.
85(1999); http://dx.doi.org/10.1063/1.369686View Description Hide Description
The behavior of excess carbon in cubic SiC films was investigated using infrared absorption spectroscopy of modes which were optically activated by defect-induced strain in the film. The results show that the excess carbon which is formed interstitially in the region of SiC grain boundaries as an interstitial phase, consists of both crystalline and amorphous phases. The crystalline phase declines and the amorphous phase grows when the growth temperature is increased above 700 °C.
85(1999); http://dx.doi.org/10.1063/1.369687View Description Hide Description
The composition dependence of the energy levels of the DX centers in heterostructures have been determined by means of Hall effect and persistent photoconductivity measurements made on gated Hall bar test structures, primarily in the indirect portion of the fundamental band gap of The energy of the DX center relative to the average of the main conduction band minima of the Brillouin zone, in the composition range, is for the DX center is resonant with the conduction band.
85(1999); http://dx.doi.org/10.1063/1.369688View Description Hide Description
Data are presented on modified spontaneous emission rates in quantum dot microcavity arrays. Three-dimensional optical confinement is achieved using apertured microcavities with square aperture sizes varied from 5 to 1 μm on a side. A maximum measured increase in the on-resonance spontaneous emission rate over that off resonance is ∼50%, and we identify this enhancement with apertured modes of the microcavity. Oscillations in the spontaneous emission rate versus wavelength correspond to spectral resonances in the higher order aperture modes.