Photoluminescence spectroscopy (PL) has been used to study the optical properties of three-dimensional quantum-sized InGaPAs islands formed by substituting phosphorus by arsenic in an InGaP layer deposited on GaAs directly during epitaxial growth. PL line of the formed array of islands is in the range of 950–1000 nm at room temperature. Studies of PL in the temperature range 78–300 K indicate a significant inhomogeneity of the island array, the presence of nonradiative recombination centers, and carrier transport between islands. We observe in the photoluminescence excitation spectra a line associated with absorption in the residual two-dimensional InGaPAs layer. Annealing of the structures results in 300% increase of the PL intensity at room temperature with an insignificant short-wavelength shift of the island PL line, and also in improvement of the homogeneity within the island array.

The influence of InGaAlAs waveguide layer composition on the photoluminescence and electroluminescence in the 1550-nm spectral range of heterostructures based on thin strained In0.74Ga0.26As quantum wells has been studied. An approach is proposed that allows based on the analysis of electroluminescence.to carry out a comparative analysis of the deferential gain in fabricated laser diodes. It is shown that decrease of the molar fraction of aluminum in waveguide InGaAlAs layers matched in lattice constant with indium phosphide leads to falling of integrated photoluminescence intensity, however, laser diodes with In0.53Ga0.31Al0.16As waveguide layers demonstrate a higher differential gain compared to laser diodes with In0.53Ga0.27Al0.20As waveguide.