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Casey Boutwell
2007 U.S. Student
Advisor: Winston Vaughan Schoenfeld
"Thermal Stability of CdZnO/ZnO Multiple Quantum Well
Active Regions"
Wurtzite CdZnO/ZnO multiple quantum wells (MQW), grown with molecular
beam epitaxy (MBE) upon a sapphire substrate with wurtzite GaN buffer at less
than 400°C, were heated using a Rapid Thermal Annealer (RTA) to temperatures
ranging from 350°C to 750°C. Room temperature Photoluminescence
characterization with a 325nm He-Cd laser showed center peak wavelength shifts of
as much as 30 nm and increase of emission intensity three fold. At 750°C the MQW
emission effectively merged indistinguishably into the barrier emission, shifting over
50 nm and increasing in intensity from the unbaked sample by about 25%. Time
dependent annealing for 180s, 360s, 540s, and 720s showed equal 10nm-12nm
blueshift for all four times with a definite increase in emission intensity. This shows
the viability of CdZnO/ZnO heterostructures for use in the near UV/Visible
wavelengths in optoelectronic devices functional for room temperature and above. ...full text
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