A Study of GaAsSb Nanowire Photodetectors
Abstract
This is a report on the investigation of bandgap tuning by GaAs/GaAsSbN/GaAs core/ multi-shell nanowires (NWs), patterned array of GaAs nanowires, ex-situ chemical passivation of GaAsSb core/shell NWs using hydrazine-sulfide solution, and nanomanipulation of NW. We have successfully demonstrated bandgap tuning up to 1.3 µm by incorporating a diluted amount of N in core-shell configured GaAs/GaAsSb/GaAs heterostructured nanowires, grown by Ga-assisted molecular beam epitaxy. NWs annealed at 750oC exhibited room temperature PL indicative of efficient annihilation of N-related defects, the nature of which was further confirmed to be point defects as ascertained by corresponding Raman spectral shift and lineshape. A significant reduction in the temperature induced shift in PL peak energy to ~32 meV was also observed over the temperature range of 4K to 300K. Growth of patterned NW arrays of GaAs have been examined and key parameters were identified for achieving all vertical NWs with 100% occupancy of holes, created by electron beam lithography for different pitches. Ex-situ passivation of the GaAs/GaAsSb core/shell nanowires by Hydrazine has produced promising results boosting the PL intensity three-fold. Investigation of NW nanomanipulation and set-up of the low frequency noise measurement are currently in progress.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 04, 2018
- Source ID
- W911NF1510160
Entities
People
- Shanthi Iyer
Organizations
- Army Contracting Command
- North Carolina Agricultural and Technical State University
- United States Army