Two-dimensional molybdenum ditelluride (MoTe2): synthesis, characterization, and application

Simple item page
dc.contributor.advisorAjayan, Pulickel Men_US
dc.creatorZhang, Xiangen_US
dc.date.accessioned2019-05-17T15:11:28Zen_US
dc.date.available2019-05-17T15:11:28Zen_US
dc.date.created2018-05en_US
dc.date.issued2018-04-19en_US
dc.date.submittedMay 2018en_US
dc.date.updated2019-05-17T15:11:29Zen_US
dc.description.abstractRecent research efforts in two-dimensional (2D) materials have shown an increasing focus on molybdenum ditelluride (MoTe2). Unlike other TMDs, MoTe2 is distinguished by the existence of two stable phases, hexagonal 2H phase and monoclinic 1T’ phase, both of which can be synthesized directly. 2H MoTe2 is a semiconductor with a band gap of ~ 1 eV, while 1T’ MoTe2 is metallic which can be transformed to a type-II Weyl semimetal at low temperature. The semiconductor-metal junction between 2H and 1T’ MoTe2 shows the potential to resolve the issue of the existence of high Schottky barrier in traditional devices. MoTe2 does not only possesses a myriad of physical properties to further unravel but also shows great potential towards various industrial applications such as analog circuits and spintronics. Here in this thesis, chapter 1 gave a brief introduction to 2D materials. Several common synthesis methods, characterization methods, and applications were discussed. Chapter 2 focused on the phase-controlled synthesis of large-area MoTe2 films and 2H/1T’ MoTe2 heterostructures by chemical vapor deposition. A series of techniques have been used to systematically characterize the synthesized MoTe2 films. In chapter 3, several types of MoTe2-based devices were fabricated and measured. We demonstrated an electrical device across the one-step-synthesized 2H/1T’ MoTe2 in-plane heterostructure, where 1T’ phase serves as the contact electrodes for the 2H phase channel. An improved current density was observed compared with deposited metal electrodes on top. In chapter 4, we studied the Raman enhancement on MoTe2 films. MoTe2-based 2D heterostructures exhibit the potential as novel platforms for surface-enhanced Raman scattering (SERS) application. Our recent efforts in the spatial phase-targeted synthesis of 2H and 1T’ MoTe2 were presented in chapter 5. This strategy was suitable not only for large-scale patterns but also for small features. In chapter 6, we used the ultrafast electron diffraction (UED) to investigate the nonradiative process in 2H MoTe2 at SLAC National Accelerator Laboratory. This thesis doesn’t only study the fundamental properties of MoTe2, but also paves the way towards the large-scale application of MoTe2 in electronic and optoelectronic devices.en_US
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationZhang, Xiang. "Two-dimensional molybdenum ditelluride (MoTe2): synthesis, characterization, and application." (2018) Diss., Rice University. <a href="https://hdl.handle.net/1911/105753">https://hdl.handle.net/1911/105753</a>.en_US
dc.identifier.urihttps://hdl.handle.net/1911/105753en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.subjectTwo-dimensional materialsen_US
dc.subjectmolybdenum ditellurideen_US
dc.subjectMoTe2en_US
dc.subjectchemical vapor depositionen_US
dc.subjectmetal-semiconductor junctionen_US
dc.subjectsurface-enhanced Raman spectroscopyen_US
dc.subjectultrafast electron diffractionen_US
dc.titleTwo-dimensional molybdenum ditelluride (MoTe2): synthesis, characterization, and applicationen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentApplied Physicsen_US
thesis.degree.disciplineNatural Sciencesen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelDoctoralen_US
thesis.degree.majorAppl Phys/Materials Sci NanoEnen_US
thesis.degree.nameDoctor of Philosophyen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
ZHANG-XIANG-DOCUMENT-2018.pdf
Size:
8.15 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 2 of 2
No Thumbnail Available
Name:
PROQUEST_LICENSE.txt
Size:
5.84 KB
Format:
Plain Text
Description:
Download
No Thumbnail Available
Name:
LICENSE.txt
Size:
2.6 KB
Format:
Plain Text
Description:
Download
Collections
Rice University Theses and Dissertations