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A dense phase of GaAs wires forms a corrugated surface in the early stages of strained growth on GaP, assembling from elongated Stranski-Krastanow islands. For a series of samples, the evolution of shape and whisker periodicity has been followed as a function of deposition time. This has been done with the help of atomic-force microscopy together with autocorrelation measurements. Transmission electron microscopy measurements support the results. The lateral wire period and long shapes are not predicted by published models, though we conclude that the island orientation is picked out by facet energy inequivalencies. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We report on a method of synthesizing arrays of individually seeded nanowires. An electron beam lithography and metal lift-off method was used to pattern InP(111)B substrates with catalysing gold particles. Vertical [inline image] nanowire arrays were then grown from the gold particles, using metal–organic vapour phase epitaxy. The lithographic nature of the method allows individual control over each nanowire. Possible applications for such deterministic and uniform arrays include producing arrays of nanowire devices, two-dimensional photonic band gap structures and field emission displays, amongst others. [ABSTRACT FROM AUTHOR]

Results on fabrication and DC-characterisation of vertical InAs nanowire wrap-gate field-effect transistor arrays with a gate length of 50 nm are presented. Each nanowire array was processed into a transistor with a systematic variation in a number of wires and wire diameter over the sample. Extensive studies have been performed on the influence of wire number and diameter on the transistor characteristics due to a high device yield (84%). In particular it is shown that the threshold voltage depends on the wire diameter, with a change in the order of 5 mV/nm. These results show the possibility of changing the transistor characteristics on the sample by altering the wire dimensions, still using only one patterning and growth sequence. [ABSTRACT FROM AUTHOR]

We report on the growth of designed heterostructures placed within semiconductor nanowhiskers, exemplified by the InAs/InP material system. Based on transmission electron microscopy, we deduce the interfaces between InAs and InP to be atomically sharp. Electrical measurements of thermionic emission across an 80-nm-wide InP heterobarrier, positioned inside InAs whiskers 40 nm in diameter, yield a barrier height of 0.6 eV. On the basis of these results, we propose new branches of physics phenomena as well as new families of device structures that will now be possible to realize and explore. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]