Technical Description: The goal of this project is to develop the epitaxial technology to grow metamorphic antimonide-based materials and study their structural, optical and electrical properties. The fundamental absorption edge of these semiconductors can vary within a wide spectral range from near to far infrared. Currently the full technological potential of antimonide-based semiconductors cannot be utilized since the direct growth of epitaxial layers is limited by the availability of the binary substrates. The large lattice mismatch between the epitaxial layers and substrate leads to high densities of crystalline defects. The approach of compositionally graded buffer layers can address this issue based on understanding of the dislocation formation and dislocation motion in soft antimonide materials. The critical factor is strain relief in the compositionally graded buffer layer confining the network of misfit dislocations in the transitional region near the substrate. The lattice constant becomes truly a design parameter unveiling fundamental advantages offered by antimonide semiconductors. The experimental studies of the optical and electrical properties of narrow bandgap bulk materials and heterostructures grown on top of metamorphic buffers are necessary to develop the fundamental knowledge of the properties of this new class of semiconductors. Non-technical Description: Antimonide-based narrow bandgap semiconductors are important materials for development of the efficient photonic and electronic devices which are suitable for a variety of industrial and military applications. The potential of this class of semiconductors can be fully utilized when the lattice constant of the device heterostructure becomes one of the design parameters. The projected studies are directly related to the problem of integration of electronics and photonics devices. The societal impact of the research is amplified by outreach activities. Undergraduate and graduate students working on development and implementation of various optical sensors will be able to utilize novel materials with rare optical and electrical properties for their original designs.
