Photoluminescence and photoluminescence-excitation spectroscopy of GaPAsN/GaP lattice-matched multiple quantum well structures

GaP1-x-yAsyNx/GaP (x = 2.0%, y = 12%) lattice-matched multiple quantum well (MQW) structures have been grown by metalorganic vapor-phase epitaxy (MOVPE). Low-temperature photoluminescence (PL) and photoluminescence excitation (PLE) measurements for the varied well widths (Lz = 36, 24, and 16 angstroms) have revealed that the quantum confinement effect to the well manifests itself only in the narrow wells whose width is comparable with or shorter than the spatial extent of the localized excitons. Higher-temperature luminescence has been drastically enhanced, where the room temperature PL intensity is estimated 103-104 times larger than in the bulk. This is due to the efficient electron confinement to the well which is brought about by the large conduction band offset ΔEc (approximately 280 meV).