Anders Mikkelsen

Lund University

"Direct atomically resolved imaging of semiconductor nanowires by Scanning Tunneling Microscopy"

Free-standing semiconductor nanowires with tailored electronic and photonic properties have a wide range of potential applications as tools and devices in physics, chemistry and biology [1]. Their most important merit is the possibility to grow a huge variety of complex vertical and lateral nanowire heterostructures in a reproducible way. Further light emitting III-V nanowires have been grown in direct contact with Si substrates, combining the excellent photonic properties of the III-V's with the most important material of consumer electronics, Silicon [2].

Using Scanning Tunneling Microscopy (STM), we have addressed both the issue of heterostructure growth, the initial growth of the nanowire on the substrate and the influence of nanowire growth on the substrates - with direct atomic scale resolution. We have applied our newly developed scheme to image individual atoms inside III-V semiconductor nanowires using a combination of STM and crystalline embedding [3].

Further we have investigated the possibilities to dramatically alter the nanowire growth by adding organic substances or changing the seed particle composition and we have studied the influence on the surrounding substrate by the Au nanowire seed particles.

[1] L. Samuelson, Mater. Today 6 (2003) 22.

[2] T. Mårtensson et al, Nano Lett 4 (2004) 1987

[3] A. Mikkelsen, et al, Nature Materials. 3 (2004) 519

MONDAY - April 24, 2006

4:10 p.m. -- Walter Lecture Hall 245