Hydrothermal method for doping of zinc oxide nanowires and fabrication of ultraviolet photodetectors

Download

index.pdf

Date

2012

Author

Afal, Ayşegül

Metadata

Show full item record

Item Usage Stats

170
views

50
downloads

Nanotechnology comprises of the understanding and control of materials and processes at the nanoscale. Among various nanostructured materials, semiconducting nanowires attract much interest for their novel physical properties and potential device applications. The unique properties of these nanowires are based on their high surface to volume ratio and quantum confinement effect. Zinc oxide, having a direct, wide bandgap and large exciton binding energy, is highly appealing for optoelectronic devices. Due to excellent optical and electrical properties, zinc oxide nanowires have been utilized to fabricate various devices such as solar cells, light emitting diodes, transistors and photodetectors. Furthermore, zinc oxide, in its natural state exhibits n-type conductivity. Addition of impurities often leads to remarkable changes in their electrical and optical properties, which open up new application areas. Among the many synthesis methods for zinc oxide nanowires, hydrothermal method is an attractive one due to its easy procedure, simple equipment and low temperature requirements. In this thesis, zinc oxide nanowires were grown and doped by hydrothermal method. Different metal dopants such as copper, silver and aluminum were used for this purpose. These metals were selected as dopants due to their effect on magnetic properties, p-type conduction and electrical conductivity of ZnO nanowires, respectively. Doped nanowires were fully characterized and the changes in their physical properties were investigated. In addition, hydrothermally synthesized pure and aluminum doped zinc oxide nanowires were used as the electrically active components in ultraviolet photodetectors. Silver nanowires were utilized as transparent electrodes. Optoelectronic properties of the detectors were examined. Effect of in-situ annealing and nanowire length was investigated. Short recovery time, around 4 seconds, with a decent on/off ratio of 2600 was obtained. This design provides a simple and cost effective approach for the fabrication of high performance ultraviolet photodetectors.

Subject Keywords

Zinc oxide., Optoelectronic devices., Optical detectors., Nanowires.

URI

http://etd.lib.metu.edu.tr/upload/12614463/index.pdf
https://hdl.handle.net/11511/21660

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Hydrothermally grown zinc oxide nanowires and their utilization in light emitting diodes and photodetectors Ateş, Elif Selen; Ünalan, Hüsnü Emrah; Department of Metallurgical and Materials Engineering (2012) Zinc oxide, with its direct wide bandgap and high exciton binding energy, is a promising material for optoelectronic devices. Quantum confinement effect and high surface to volume ratio of the nanowires imparts unique properties to them and makes them appealing for researchers. So far, zinc oxide nanowires have been used to fabricate various optoelectronic devices such as light emitting diodes, solar cells, sensors and photodetectors. To fabricate those optoelectronic devices, many different synthesis metho...
Opto-thermoelectric nanotweezers LIN, Linhan; WANG, Mingsong; PENG, Xiaolei; LISSEK, Emanuel N.; MAO, Zhangming; SCARABELLI, Leonardo; ADKINS, Emily; Coskun, Sahin; Ünalan, Hüsnü Emrah; KORGEL, Brian A.; LIZ-MARZAN, Luis M.; FLORIN, Ernst-Ludwig; ZHENG, Yuebing (Springer Science and Business Media LLC, 2018-04-01) Optical manipulation of plasmonic nanoparticles provides opportunities for fundamental and technical innovation in nanophotonics. Optical heating arising from the photon-to-phonon conversion is considered as an intrinsic loss in metal nanoparticles, which limits their applications. We show here that this drawback can be turned into an advantage, by developing an extremely low-power optical tweezing technique, termed opto-thermoelectric nanotweezers. By optically heating a thermoplasmonic substrate, a light-...
Plasmonic resonances in sub-terahertz fishnet metamaterial based on complementary hexagonal resonator Yuksek, Yahya; Demir, S. Mahircan; Sabah, Cumali (Elsevier BV, 2019-01-01) Exploration of the perfect combination between metamaterials (MTMs) and plasmonics has paved the way of the new innovations in electromagnetic and communication engineering, especially in sub-THz spectroscopy. In order to contribute to such developments, plasmonic resonances in sub-THz fishnet MTM on the basis of complementary hexagonal resonator structure is investigated in this paper. The design, in which method of removing hexagonal structure is applied, has been performed based on finite simulation tech...
Photoluminescence specroscopy of CdS and GaSe Seyhan, Ayşe; Turan, Raşit; Department of Physics (2003) With the use of photoluminescence (PL) spectroscopy one can able to get a great deal of information about electronic structure and optical processes in semiconductors by the aid of optical characterization. Among various compound semiconductors, Cadmium Sulfide (CdS) and Gallium Selenide (GaSe) are interesting materials for their PL emissions. Particularly, due to its strong anisotropy, investigation of GaSe necessitates new experimental approaches to the PL technique. We have designed, fabricated and used ...
Electronic structure of carbon nanotubes: AM1-RHF calculations Erkoç, Şakir; Turker, L (Elsevier BV, 1999-07-01) We have investigated the electronic structure of optimized open-ended single-wall carbon nanotubes with armchair and zigzag geometries. The calculations were performed using AM1-RHF semiempirical molecular orbital method. It has been found that the density of states of the zigzag model is more sensitive to the tube size than that of the armchair model.

Citation Formats

A. Afal, “Hydrothermal method for doping of zinc oxide nanowires and fabrication of ultraviolet photodetectors,” M.S. - Master of Science, Middle East Technical University, 2012.