Dissertation
Carrier dynamics in III-V compound mid-infrared semiconductor nanowires, superlattices and quaternaries
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Summer 2020
DOI: 10.17077/etd.005560
Abstract
Contactless time-resolved optical measurements have minor detrimental effect on the optical properties on the semiconductor and serve as a useful tool for material characterization. Carrier recombination mechanisms and light emission properties will be investigated in order to determine the potential applications for semiconductor materials.
Indium arsenide (InAs)-based nanowires (NWs) have high electron mobility which make them a promising material for high-speed electronic devices such as transistors. Furthermore, the low effective refractive index for NWs facilitates light extraction typically limited by total internal reflection, indicating the potential applications for NW light sources. However, the question of whether these types of NWs are suitable for Mid-infrared (MIR) optoelectronic applications remain open since no reports have been found about the carrier dynamics in InAs-based core-shell NWs, or the interplay of carrier lifetime and non-radiative recombination with passivation. The individual contributions of radiative and nonradiative recombination including Shockley-Read-Hall (SRH) and Auger recombination to bulk recombination have not been investigated. A thorough understanding of charge carrier recombination mechanisms in InAs-based NWs is therefore needed.
Other than semiconductor nanowires, compound bulk materials are still of interest. Gallium (Ga)-free indium arsenide/indium arsenide antimonide (InAs/InAsSb) type-II superlattices (T2SLs) have been reported to be less plagued by SRH recombination than InAs/GaSb T2SLs, and hence more suitable for MIR photodetector devices. The dependence of carrier lifetime on parameters including layer thickness and alloy composition has been demonstrated. Yet for detectors used in space, the effect of strong irradiation has to be studied. In near-infrared range, GaInAsSb quaternary alloy is considered as one of the most promising materials for photodetector. However, a thorough understanding of the carrier recombination mechanism is still missing. In this dissertation, contactless optical characterization including ultrafast pump-probe spectroscopy, quantum efficiency and photoluminescence measurements will be conducted to investigate the carrier dynamics in the aforementioned III-V semiconductors.
Details
- Title: Subtitle
- Carrier dynamics in III-V compound mid-infrared semiconductor nanowires, superlattices and quaternaries
- Creators
- Xinxin Li
- Contributors
- John P. Prineas (Advisor)Craig Pryor (Committee Member)David Andersen (Committee Member)Fatima Toor (Committee Member)Markus Wohlgenannt (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Physics
- Date degree season
- Summer 2020
- DOI
- 10.17077/etd.005560
- Publisher
- University of Iowa
- Number of pages
- xv, 127 pages
- Copyright
- Copyright 2020 Xinxin Li
- Language
- English
- Description illustrations
- color illustrations
- Description bibliographic
- Includes bibliographical references (pages 115-127).
- Public Abstract (ETD)
Semiconductor materials have been widely used for optoelectronic and photovoltaic devices. Recently, semiconductor applications at the nanoscale have been of interest to many groups. Optical properties of semiconductor nanowires have been investigated to determine their potential applications in near-infrared range.
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9983987894902771
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