Optical Properties of Three-Dimensional InGaP(As) Islands Formed by Substitution of Fifth-Group Elements

The optical properties of three-dimensional quantum-size InGaPAs islands, which are formed by substitution of phosphorous by arsenic in an InGaPAs layer deposited on GaAs directly during the epitaxial growth, are studied by photoluminescence (PL) spectroscopy. The PL line of the formed array of island lies in the range of 950–1000 nm at room temperature. The PL studies in the temperature range of 78–300 K indicate significant inhomogeneity of the island array, existence of nonradiative recombination centers, and transport of carriers between islands. The photoluminescence excitation spectra exhibit a line related to the absorption in the residual two-dimensional InGaPAs layer. Annealing of the structures allowed us to increase the PL intensity at room temperature up to 300% with a slight short-wavelength shift of the island emission line and to improve the homogeneity inside the island array.