Investigation of Titanium Nitride/Titanium Dioxide Thin-Film Photodetector Fabricated by Atomic Layer Chemical Vapor Deposition
| Autor: | Chen, Chi-Hsuan, 陳紀軒 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 Typically, to generate photo-excited carriers from a semiconductor, enough absorption for the incident photons is necessary. In principle, the optical absorption is determined by the band gap of the material. As long as the energy of the incoming photons is larger than the band gap, it will be absorbed. This leads to the fact that it can convert the light energy into electrical energy. For a wide-band-gap material like titanium dioxide (TiO2), the energy of both visible and infrared light are obviously too low to overcome the band gap of it. Therefore, in this research we use Atomic Layer Chemical Vapor Deposition System to deposit a titanium nitride (TiN) thin film on top of the TiO2 film as the light absorption layer which can help overcome the limitation of the band gap. Also, indium tin oxide (ITO) is used as the electron transport layer in this case. Through multiple measurements and analyses, it is found that there is a significant photo-response of TiN from ultraviolet to infrared region. However, the electron transport characteristics are greatly affected by the defect levels in the band gap of TiO2, such as large dark current and delayed response. The mechanism of photoelectron excitation and transmission are quite special. If it is to be served as a photodetector, better process conditions must be found to reduce the effect of defect level. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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