Expanding the Optical Capabilities of Germanium in the Infrared Range Through Group IV and III-V-IV Alloy Systems
abstract: The work described in this thesis explores the synthesis of new semiconductors in the Si-Ge-Sn system for application in Si-photonics. Direct gap Ge1-ySny (y=0.12-0.16) alloys with enhanced light emission and absorption are pursued. Monocrystalline layers are grown on Si platforms via epit...
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ndltd-asu.edu-item-515822019-02-02T03:01:05Z Expanding the Optical Capabilities of Germanium in the Infrared Range Through Group IV and III-V-IV Alloy Systems abstract: The work described in this thesis explores the synthesis of new semiconductors in the Si-Ge-Sn system for application in Si-photonics. Direct gap Ge1-ySny (y=0.12-0.16) alloys with enhanced light emission and absorption are pursued. Monocrystalline layers are grown on Si platforms via epitaxy-driven reactions between Sn- and Ge-hydrides using compositionally graded buffer layers that mitigate lattice mismatch between the epilayer and Si platforms. Prototype p-i-n structures are fabricated and are found to exhibit direct gap electroluminescence and tunable absorption edges between 2200 and 2700 nm indicating applications in LEDs and detectors. Additionally, a low pressure technique is described producing pseudomorphic Ge1-ySny alloys in the compositional range y=0.06-0.17. Synthesis of these materials is achieved at ultra-low temperatures resulting in nearly defect-free films that far exceed the critical thicknesses predicted by thermodynamic considerations, and provide a chemically driven route toward materials with properties typically associated with molecular beam epitaxy. Silicon incorporation into Ge1-ySny yields a new class of Ge1-x-ySixSny (y>x) ternary alloys using reactions between Ge3H8, Si4H10, and SnD4. These materials contain small amounts of Si (x=0.05-0.08) and Sn contents of y=0.1-0.15. Photoluminescence studies indicate an intensity enhancement relative to materials with lower Sn contents (y=0.05-0.09). These materials may serve as thermally robust alternatives to Ge1-ySny for mid-infrared (IR) optoelectronic applications. An extension of the above work is the discovery of a new class of Ge-like Group III-V-IV hybrids with compositions Ga(As1–xPx)Ge3 (x=0.01-0.90) and (GaP)yGe5–2y related to Ge1-x-ySixSny in structure and properties. These materials are prepared by chemical vapor deposition of reactive Ga-hydrides with P(GeH3)3 and As(GeH3)3 custom precursors as the sources of P, As, and Ge incorporating isolated GaAs and GaP donor-acceptor pairs into diamond-like Ge-based structures. Photoluminescence studies reveal bandgaps in the near-IR and large bowing of the optical behavior relative to linear interpolation of the III-V and Ge end members. Similar materials in the Al-Sb-B-P system are also prepared and characterized. The common theme of the above topics is the design and fabrication of new optoelectronic materials that can be fully compatible with Si-based technologies for expanding the optoelectronic capabilities of Ge into the mid-IR and beyond through compositional tuning of the diamond lattice. Dissertation/Thesis Wallace, Patrick Michael (Author) Kouvetakis, John (Advisor) Menendez, Jose (Committee member) Trovitch, Ryan (Committee member) Arizona State University (Publisher) Chemistry Materials Science Physics germanium germanium tin GeSn group IV III-V-IV semiconductor eng 192 pages Doctoral Dissertation Chemistry 2018 Doctoral Dissertation http://hdl.handle.net/2286/R.I.51582 http://rightsstatements.org/vocab/InC/1.0/ 2018 |
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English |
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Doctoral Thesis |
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Chemistry Materials Science Physics germanium germanium tin GeSn group IV III-V-IV semiconductor |
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Chemistry Materials Science Physics germanium germanium tin GeSn group IV III-V-IV semiconductor Expanding the Optical Capabilities of Germanium in the Infrared Range Through Group IV and III-V-IV Alloy Systems |
description |
abstract: The work described in this thesis explores the synthesis of new semiconductors in the Si-Ge-Sn system for application in Si-photonics. Direct gap Ge1-ySny (y=0.12-0.16) alloys with enhanced light emission and absorption are pursued. Monocrystalline layers are grown on Si platforms via epitaxy-driven reactions between Sn- and Ge-hydrides using compositionally graded buffer layers that mitigate lattice mismatch between the epilayer and Si platforms. Prototype p-i-n structures are fabricated and are found to exhibit direct gap electroluminescence and tunable absorption edges between 2200 and 2700 nm indicating applications in LEDs and detectors. Additionally, a low pressure technique is described producing pseudomorphic Ge1-ySny alloys in the compositional range y=0.06-0.17. Synthesis of these materials is achieved at ultra-low temperatures resulting in nearly defect-free films that far exceed the critical thicknesses predicted by thermodynamic considerations, and provide a chemically driven route toward materials with properties typically associated with molecular beam epitaxy.
Silicon incorporation into Ge1-ySny yields a new class of Ge1-x-ySixSny (y>x) ternary alloys using reactions between Ge3H8, Si4H10, and SnD4. These materials contain small amounts of Si (x=0.05-0.08) and Sn contents of y=0.1-0.15. Photoluminescence studies indicate an intensity enhancement relative to materials with lower Sn contents (y=0.05-0.09). These materials may serve as thermally robust alternatives to Ge1-ySny for mid-infrared (IR) optoelectronic applications.
An extension of the above work is the discovery of a new class of Ge-like Group III-V-IV hybrids with compositions Ga(As1–xPx)Ge3 (x=0.01-0.90) and (GaP)yGe5–2y related to Ge1-x-ySixSny in structure and properties. These materials are prepared by chemical vapor deposition of reactive Ga-hydrides with P(GeH3)3 and As(GeH3)3 custom precursors as the sources of P, As, and Ge incorporating isolated GaAs and GaP donor-acceptor pairs into diamond-like Ge-based structures. Photoluminescence studies reveal bandgaps in the near-IR and large bowing of the optical behavior relative to linear interpolation of the III-V and Ge end members. Similar materials in the Al-Sb-B-P system are also prepared and characterized. The common theme of the above topics is the design and fabrication of new optoelectronic materials that can be fully compatible with Si-based technologies for expanding the optoelectronic capabilities of Ge into the mid-IR and beyond through compositional tuning of the diamond lattice. === Dissertation/Thesis === Doctoral Dissertation Chemistry 2018 |
author2 |
Wallace, Patrick Michael (Author) |
author_facet |
Wallace, Patrick Michael (Author) |
title |
Expanding the Optical Capabilities of Germanium in the Infrared Range Through Group IV and III-V-IV Alloy Systems |
title_short |
Expanding the Optical Capabilities of Germanium in the Infrared Range Through Group IV and III-V-IV Alloy Systems |
title_full |
Expanding the Optical Capabilities of Germanium in the Infrared Range Through Group IV and III-V-IV Alloy Systems |
title_fullStr |
Expanding the Optical Capabilities of Germanium in the Infrared Range Through Group IV and III-V-IV Alloy Systems |
title_full_unstemmed |
Expanding the Optical Capabilities of Germanium in the Infrared Range Through Group IV and III-V-IV Alloy Systems |
title_sort |
expanding the optical capabilities of germanium in the infrared range through group iv and iii-v-iv alloy systems |
publishDate |
2018 |
url |
http://hdl.handle.net/2286/R.I.51582 |
_version_ |
1718970009284247552 |