Formation Energies of Native Point Defects in Strained layer Superlattices (Postprint)
Abstract
We develop a theoretical approach that employs first-principles Hamiltonian, tight-binding Hamiltonian, and Greens function techniques to obtain energy levels arising from native point defects (NPDs) in InAs-GaSb and InAs-InAs1-x Sb x strained layer superlattice (SLS) systems. In particular, we consider 4 types of NPDs anion vacancy, cation vacancy, anion anti-site, cation anti-site, isoelectronic substitution at anion sites (Sb at As site and As at Sb site) in the InAs, GaSb compound regions, and additional three types of defectscation at the second anion site, second anion at the cation site, and second anion vacancy in InAs1 x Sb x alloy region of the SLS. For a selected few designs, we study NPDs both in the bulk region and near the interfaces of the SLS. We have considered 12 designs of InAs-GaSb systems and 2 designs of InAs-InAs 0.7 Sb 0.3 systems lattice matched to GaSb substrate. The calculated defect levels not only agree well with available measurements but also reveal the connection between mid-gap levels and specific NPDs. We further calculate defect formation energies both in compounds and for all superlattices considered above.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 05, 2017
- Accession Number
- AD1041793
Entities
People
- Srini Krishnamurthy
- Zhi-gang Yu
Organizations
- Washington State University Spokane