Dilute Nitride GaAsSbN/GaAs Nanowires for Infrared Photodetectors
Abstract
Dilute Nitride GaAsSbN/GaAs Nanowires for Infrared PhotodetectorsObjective:The objective of this proposal is to develop high-quality vertical dilute antimonide-nitride materials and demonstate p-i-n junction photodetector devices operating in the 1.0 ~ 1.7 ~m region for next-generation nanoscale optoelectronic devices. The comprehensive study of these nanowires (NWs) will provide an in-depth understanding of the opto-electronic properties of the dilute nitride materials in the nanowire configuration.Approach:The proposed work is focused on comprehensive investigation of the dilute nitride GaAsSbN nanowire (NW) ensemble and single NW-based photodetectors spanning a wavelength range from 1.0 ~m to 1.7 ~m for use in the next generation of NW-based photodetectors. The enabling growth technology will be molecular beam epitaxy, as this technique enables precise control of the constituent elemental flux required to meet the stringent band gap engineering demands of the mixed As-Sb based nitride nanostructures. The vapor-liquid-solid growth mode will be used via a self-catalyzed process. The advantage of this over the Au-catalyzed growth process has been well documented in the literature. Vertically-aligned ensemble NWs of GaAsSbN in both radial and axial configurations grown on (111) Si substrates will be investigated.Merit/Naval Relevance:This is a well-written proposal, demonstrating a good understanding of nanowire growth and materials engineering of dilute-nitride arsenide/antimonide heterostructures that can lead to band gaps in the short-wavelength IR region for application to photodetectors. Prof. Iyer~s group is in the Electrical Engineering Department at North Carolina A & T State University, an HBCU/MI institution. They have published several journal papers on dilute nitride nanowires grown by molecular beam epitaxy in the last three years. The group includes a permanent research associate as well as graduate and undergraduate students. They have the personnel and infrastructure to successfully complete the proposed research. The basic research and potential applications (detectors in the SWIR range) are relevant to the ONR Electromagnetic Materials Program. SOW:Year 1. Efforts in the first 12-month period have three tasks. The first of which will consist of red shifting the wavelength and determining the maximum red shift that can be achieved in axial and core-shell configurations before any severe degradation in the photoluminescence (PL) spectra sets in. The second task will be effect of in-situ annealing and ex-situ annealing in N ambient to improve the characteristics of the NWs. Third, the use of AlGaAs shell NWs will be investigated to enhance the PL efficiency. They will be characterized by low temperature micro PL, XRD, Raman, SEM EDX, TEM images in different modes. The experimental work will be complemented throughout by theoretical simulation. The fabrication of photoconducting devices will also begin. The growths of the semiconductors on the substrate template with graphene will be initiated during this period. Investigation of graphene as contact material will also begin during this period.Year 2. Efforts in the second 12-month duration will be to fine tune the growth window to get improved PL performance and to further red shift the wavelength to reach as close to 1.6 ~m as possible by using different growth tricks such as growth interruption and inserts. GaSb growth and GaSbN will also be examined to cover the entire wavelength up to 1.8 ~m. Improvement in the passivated NWs will also be investigated. Detailed material characterization as in Year 1 will be carried out. Photoconducting device at 1.3 ~m will be demonstrated. PIN device fabrication and characterization on 1.3 ~m will also begin. On the seed project, efforts will be made to identify the promising template for the successful growth of epitaxial GaAs NWs on graphene and the effect of graphene contacts on the performance of the device.Year 3. During
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141612720
Entities
People
- Shanthi Iyer
Organizations
- North Carolina Agricultural and Technical State University
- Office of Naval Research
- United States Navy