Study and fabrication of two types of wide-bandgap semiconductor-based UV photodetectors
| Autor: | Jung-Shan Liou, 劉榕珊 |
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| Rok vydání: | 2016 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 104 The ultraviolet (UV) is easy to be absorbed by various materials because its high energy and short wavelength. Because of the small bandgap and low responsivity, the traditional semiconductor material is difficult to be fabricated as UV photodetector. Hence, in this paper, we study two types of wide-bandgap semiconductor-based: gallium nitride (GaN) and gallium oxide (Ga2O3). We design GaN-based phototransistors and Ga2O3-based photoconductors with respective structure to fabricate and measure UV photodetectors. As a result, the fabrication of two types of semiconductor-based UV photodetectors, the peak external quantum efficiency (EQE) can be more than 500% and the peak responsivity is 1.77 A/W for GaN-based phototransistors at a reverse bias of 1.56 V. The peak EQE can be more than 1800% and the peak responsivity is 5.7 A/W for bias voltages up to 4.71 V with its peak-wavelength is about 382 nm and the cut-off wavelength is about 415 nm. For Ga2O3-based photoconductors at the wavelength of 254 nm light irradiation, at a bias voltage of 5 V, the EQE about 48%, corresponding to the average responsivity of 0.1 A/W; when the bias voltage up to 15V, the best EQE is 4604%, corresponding to responsivity of 9.43 A/W. The EQE measured by the two types of semiconductor-based structures are more than 100%, which proves that the element has a high internal gain. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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