Dr' JiWon Oh

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By Dr. Ji-Won Oh
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Atomic Force Microscope Image of Atomic Steps on
Atomically flat (110) GaAs QW
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Ti-Sa Ext.(730nm) with uniform excitation
PL
Ti-Sa
mm
Atomically Flat
mm
6nm
6.8 mm
GaAs
29 AlGaAs
AlGaAs
mm
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PL image spectra (4K)
Energy transfer dynamics among islands Any
dependence on temp and density of steps in ldiff?
mm
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PL image spectra (4K)
mm
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At 30K t4000 ps m4000
By Hilmer et. al. Phys. Rev. B.42. 3220-3223
(1990)
in our data
Longer diffusion length
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PL Mission to Investigate
Point excitation of Surface Steps FWHM of PL
spectra from Individual Islands and pits Any
dependence on size and steps ?
6.8 mm
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Spatially Uniform point excitation beam shape
accomplished with spatial filter
But, Optimization of microscopic PL
experiments Still not resolve n23
spectra and thick spectra compared to previous
experiments need to find out excitation
intensity which is weak enough not to cause
negative factors in PL measurements and analysis
and sharp cut filter system passing spectra
between 750 nm 800 nm only.