Mastery of semiconductor thin films gave us the integrated circuit,
optical information storage, flat panel displays and fiber optic
communications.  On the immediate horizon, thin-film technology is
poised to deliver a solid-state replacement for incandescent and
fluorescent lighting.  These mature and soon-to-be-realized
technologies have been made possible by synthesis techniques and
boundary conditions that differ markedly from those of bulk materials.
Will the next series of solid-state revolutions be derived from
mastery of semiconducting nanowires?  As in the transition from bulk
to thin-film materials, the evolution from thin-films to nanowires
(<~100 nm in diameter) involves an increase in the number of confined
dimensions, a new spectrum of synthesis techniques, and substantially
altered elastic and electronic boundary conditions.  In this talk, I
will highlight the opportunities and challenges presented by
semiconductor nanowires by focusing on three issues: i) the requisite
nonequilibrium nature of nanowire synthesis techniques, ii) the
challenge of preserving the continuous high-aspect-ratio nanowire
morphology through synthesis, processing and integration, and iii) the
opportunity to exploit an expanded palate of coherent
lattice-mismatched longitudinal heterostructures in energy conversion
devices for solid-state cooling and solid-state lighting.

Biosketch:   

Tim Sands holds a joint appointment in Materials Engineering and
Electrical & Computer Engineering at Purdue University.  Before
joining the faculty at Purdue, he was a professor of Materials Science
& Engineering at the University of California, Berkeley (1993-2002)
and a member of technical staff and research group director at Bell
Communications Research (Bellcore) in Red Bank NJ (1984-1993).  His
current research focuses on enhancing the functionality of
microsystems through heterogeneous integration at the nano- and
microscales.