GAAS1-XPX/GAAS QUANTUM-WELL STRUCTURES WITH TENSILE-STRAINED BARRIERS

An investigation of GaAs QW's with tensile-strained GaAsP barriers grown on GaAs substrates by organometallic vapor phase epitaxy is reported. We demonstrate that this system permits light- and heavy-hole valence bands to be approximately merged within a wide range of well widths and strains, thereby increasing the yield of devices requiring these characteristics. A few series of quantum wells with three phosphorus compositions (6%, 9%, and 19%) were grown and studied by photoluminescence and polarized photoluminescence excitation spectroscopy. We compared our experimentally determined conduction band to heavy-hole and light-hole transition energies with finite potential well calculations utilizing a previously developed strain dependent band offset model. We obtained excellent agreement between experimental and calculated results without any adjustment or fitting of parameters.