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       SEMINAR OF THE LABORATORY FOR COMPUTER DESIGN OF MATERIALS
        Institute for Computational Sciences and Informatics
		CSI 929  (http://science.gmu.edu/physics)
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	A Structurally Modified Semiconductor Quantum Well of GaAs/AlAs.

			      Thomas Forbang
		Laboratory for Computer Design of Materials
	   Institute for Computational Sciences and Informatics 
			George Mason University 
				
	The effects of structural modifications of semiconductor quantum wells
on phonon modes and electron-phonon interactions are being studied. Results
show
additional phonon modes due to the presence of thin layers of AlAs in the
GaAs/AlAs well system. We have shown that these new phonon modes modify the
contributions of confined and interface phonons to the electron-phonon
scattering matrix elements. In addition, we have also calculated the relaxation
time of electrons due to phonon scattering in the structurally modified
structures and  simple quantum wells.

	The most significant question, from a technological standpoint, is
whether structural modifications actually provide control of electron-phonon
scattering in order to increase electron mobility in semiconductor materials.
The answer to this question is currently the principal goal of our research.

	                   Monday , April 29 1996
                                  5:00 pm
                          Room 206, Science & Tech. I
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