| Narrow gap compound semiconductors and their alloys have shown significant promise for a wide range of applications, including long wavelength light emitters, high performance electronic devices, and high efficiency solar cells. A fundamental understanding of correlations between the synthesis, structure, and properties is essential for the optimization of device performance. In this thesis work, these issues are investigated in two narrow gap compound semiconductor systems.; In a highly mismatched InSb/GaAs system, the evolution of the structural properties, including the surface and interface roughness, residual strain, and threading dislocations is examined. The relative effects of these structural properties on the electron mobility of the films is also investigated. The InSb films exhibit a thickness-dependent electron mobility, which is determined to be due to scattering of free carriers from threading dislocations. Other structural factors do not apparently play a significant role in limiting the electron mobility of the films. In addition, the strain field associated with the dislocations, rather than the carrier depletion region apparently surrounding them, is shown to scatter the free carriers and limit the electron mobility.; In addition, the structure and optical properties of (InGa)(AsN) nanostructures synthesized by N ion implantation into GaAs and InAs are studied. High-resolution transmission electron microscopy indicates the formation of crystalline GaN-rich nanostructures surrounded by disordered matrices. As the annealing temperature increases, the nanostructure size increases while the size distributions are self-similar and the volume fraction remains constant. Thus, the nanostructure coarsening process is considered to be governed by Ostwald ripening, with an activation energy of ∼1.0 eV. These nanostructures exhibit significant photoluminescence in the near-infrared range, which may be due to the incorporation of a small amount of As in GaN. Furthermore, a novel materials integration method, ion-cut-synthesis, is developed. Using high-temperature annealing, a nanostructure layer may be simultaneously synthesized and cleaved from the substrate. The N2 bubbles formed at the layer/substrate interface during the annealing provide the cleavage force. The ion-cut-synthesis process provides a new opportunity for the integration of the nanostructures with a variety of substrates. |
