Electronic and optical properties of highly boron-doped epitaxial Ge/AlAs(001) heterostructures
Abstract
The impact of elemental boron (B) doping on the structural, optical, and magnetotransport properties of epitaxial Ge/AlAs/GaAs(001) heterostructures, grown by solid-source molecular beam epitaxy, was comprehensively investigated. Cross-sectional transmission electron microscopy analysis revealed atomically abrupt Ge:B/AlAs and AlAs/GaAs heterointerfaces and a lack of observable long-range defect formation or B segregation in the epitaxial Ge:B layer. Spectral broadening observed in the measured temperature-dependent photoluminescence spectra suggested valence band mixing during recombination, implying a splitting of the valence band heavy- and light-hole degeneracy due to residual strain resulting from substitutional B incorporation in the Ge epilayer. Temperature-dependent magnetotransport analysis of the B-doped Ge thin films exhibited the tell-tale signature of antilocalization, indicating observable spin–orbit interaction in the Ge:B system. Moreover, the temperature- and magnetic field-dependent magnetotransport results indicate the presence of single-carrier, p-type conduction in the Ge:B film, further affirming the successful incorporation and activation of B at a high concentration (∼4 × 1019 cm−3) and elimination of parallel conduction via the large-bandgap AlAs buffer. Together, these results provide insights into the effects of heavy doping (via elemental solid-source doping) on Ge-based heterostructures and their feasibility in future electronic and photonic applications.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 18, 2020
- Source ID
- 10.1063/1.5130567
Entities
People
- Giti Khodaparast
- Jean J Heremans
- Jheng-sin Liu
- Mantu K Hudait
- Michael A. Meeker
- Michael Clavel
- Shuvodip Bhattacharya
- Yuantao Xie
Organizations
- Air Force Office of Scientific Research
- National Science Foundation
- Virginia Tech