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Growth of III-V semiconductor quantum wells by organometallic chemical vapor deposition
Abstract
III-V semiconductor quantum wells (QW) were grown by atmospheric pressure organometallic chemical vapor deposition, and characterized using low-temperature photoluminescence (PL), and photoluminescence excitation (PLE) spectroscopies. QWs composed of three material systems were studied: Al$\sb{x}$Ga$\sb{1-x}$As/GaAs, in which the constituent layers are essentially lattice matched, pseudomorphic GaAs/In$\sb{x}$Ga$\sb{1-x}$As, in which the In$\sb{x}$Ga$\sb{1-x}$As well layer is under biaxial compression, and pseudomorphic Al$\sb{x}$Ga$\sb{1-x}$As/GaAs$\sb{1-y}$P$\sb{y}$ in which the GaAs$\sb{1-y}$P$\sb{y}$ well layer is under biaxial tension. For each of the material systems, QW samples exhibited sharp, intense PL and PLE peaks corresponding to quantized ground-state excitonic transitions, whose energies agreed well with those predicted by a simple one-dimensional square-well model (that included strain effects if appropriate) for QW widths as narrow as 10 A. Saturation effects, including a reduction of energy broadening, and a decrease in the separation between heavy- and light-hole exciton energies, were observed in very narrow ($\approx$20 A or less) Al$\sb{x}$Ga$\sb{1-x}$As/GaAs and GaAs/In$\sb{x}$Ga$\sb{1-x}$As QWs. For GaAs/In$\sb{x}$Ga$\sb{1-x}$As QW samples, effects related to strain-induced layer roughening were observed as x was increased. The feasability of tailoring the relative energies of heavy- and light-hole excitons was demonstrated in various Al$\sb{0.35}$Ga$\sb{0.65}$As/GaAs$\sb{1-y}$P$\sb{y}$ QWs. The critical layer thickness for misfit dislocation formation was investigated, and for both strained material systems it was found that relaxation was sluggish and/or inhomogeneous. Finally, the effects of varying growth conditions, including growth temperature, AsH$\sb3$ partial pressure, growth interruption time, were studied.
Subject Area
Electrical engineering|Condensed matter physics|Materials science
Recommended Citation
Bertolet, Daniel Cook, "Growth of III-V semiconductor quantum wells by organometallic chemical vapor deposition" (1990). Doctoral Dissertations Available from Proquest. AAI9022664.
https://scholarworks.umass.edu/dissertations/AAI9022664