Dr. Howard Jackson, Professor of Physics at the University of Cincinnati, will discuss “Probing the Band Structure and Carrier Dynamics of Single Semiconductor Nanowires” at the Condensed Matter & Surface Sciences Colloquium on Thursday, Sept. 19, at 4:10 p.m. in Walter Lecture Hall 245.
“Semiconductor nanowires represent a remarkably versatile class of materials with the potential for illuminating new physics as well providing new technological advances,” he says. “After a brief introduction to semiconductor nanowires, we present one example of a semiconductor nanowire heterostructure to illustrate the rich possibilities of these systems to both reveal basic physics and suggest potential applications. Then we probe the band structure and carrier dynamics of simple GaAs and InP nanowires using a very old but now newly imagined optical technique, namely Rayleigh scattering.
“We present results from cw photomodulated Rayleigh scattering measurements of single GaAs and InP nanowires from which their electronic structure can be obtained. We then present some very recent picosecond pump-probe measurements of Rayleigh scattering from GaAs and InP nanowires which show that these differential spectra are sensitive indicators of both the density and temperature of electron-hole pairs in a single nanowire. With the help of a semi-phenomenological model, we show that both the photoexcited carrier density and the carrier temperature as a function of time can be obtained directly from the transient Rayleigh scattering data.”
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