2026-05-19T02:53:12Zhttps://keep.lib.asu.edu/oai/requestoai:keep.lib.asu.edu:node-1558772024-12-20T18:25:12Zoai_pmh:alloai_pmh:repo_items155877
https://hdl.handle.net/2286/R.I.45593
http://rightsstatements.org/vocab/InC/1.0/
All Rights Reserved
2017
xii, 81 pages : illustrations (some color)
Doctoral Dissertation
Academic theses
Text
eng
Peng, Jhih-hong
Yu, Hongbin
Roedel, Ronald
Goryll, Michael
Zhao, Yuji
Arizona State University
Partial requirement for: Ph.D., Arizona State University, 2017
Includes bibliographical references (pages 71-81)
Field of study: Electrical engineering
Zinc telluride (ZnTe) is an attractive II-VI compound semiconductor with a direct<br/><br/>bandgap of 2.26 eV that is used in many applications in optoelectronic devices. Compared<br/><br/>to the two dimensional (2D) thin-film semiconductors, one-dimensional (1D)<br/><br/>nanowires can have different electronic properties for potential novel applications.<br/><br/>In this work, we present the study of ZnTe nanowires (NWs) that are synthesized<br/><br/>through a simple vapor-liquid-solid (VLS) method. By controlling the presence or<br/><br/>the absence of Au catalysts and controlling the growth parameters such as growth<br/><br/>temperature, various growth morphologies of ZnTe, such as thin films and nanowires<br/><br/>can be obtained. The characterization of the ZnTe nanostructures and films was<br/><br/>performed using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy<br/><br/>(EDX), high- resolution transmission electron microscope (HRTEM), X-ray<br/><br/>diffraction (XRD), photoluminescence (PL), Raman spectroscopy and light scattering<br/><br/>measurement. After confirming the crystal purity of ZnTe, two-terminal diodes and<br/><br/>three-terminal transistors were fabricated with both nanowire and planar nano-sheet<br/><br/>configurations, in order to correlate the nanostructure geometry to device performance<br/><br/>including field effect mobility, Schottky barrier characteristics, and turn-on<br/><br/>characteristics. Additionally, optoelectronic properties such as photoconductive gain<br/><br/>and responsivity were compared against morphology. Finally, ZnTe was explored in<br/><br/>conjunction with ZnO in order to form type-II band alignment in a core-shell nanostructure.<br/><br/>Various characterization techniques including scanning electron microscopy,<br/><br/>energy-dispersive X-ray spectroscopy , x-ray diffraction, Raman spectroscopy, UV-vis<br/><br/>reflectance spectra and photoluminescence were used to investigate the modification<br/><br/>of ZnO/ZnTe core/shell structure properties. In PL spectra, the eliminated PL intensity<br/><br/>of ZnO wires is primarily attributed to the efficient charge transfer process<br/><br/>occurring between ZnO and ZnTe, due to the band alignment in the core/shell structure. Moreover, the result of UV-vis reflectance spectra corresponds to the band<br/><br/>gap energy of ZnO and ZnTe, respectively, which confirm that the sample consists of<br/><br/>ZnO/ZnTe core/shell structure of good quality.
Engineering
Electrical Engineering
Nanostructures
Nanowires
polycrystalline
Thin films
VLS
ZnTe
Nanostructures
Nanowires
Polycrystals
Thin films
Chemical vapor deposition
Zinc telluride
ZnTe nanostructural synthesis for electronic and optoelectronic devices