Origin of fast-response photocurrent in ZnO thin film
| Autor: | Yudi Darma, Muhammad Abiyyu Kenichi Purbayanto, Takashige Aono, Eka Nurfani, Kouichi Takase |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Photocurrent Materials science Photoluminescence business.industry Schottky barrier Organic Chemistry 02 engineering and technology Sputter deposition 021001 nanoscience & nanotechnology 01 natural sciences Crystallographic defect Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Inorganic Chemistry 0103 physical sciences Optoelectronics Electrical and Electronic Engineering Physical and Theoretical Chemistry Thin film 0210 nano-technology business Spectroscopy Absorption (electromagnetic radiation) |
| Zdroj: | Optical Materials. 84:453-458 |
| ISSN: | 0925-3467 |
| Popis: | We study the origin of fast-response photocurrent in ZnO system grown by dc-unbalanced magnetron sputtering. Current-voltage (I-V) measurements show that ZnO thin film is sensitive to UV–visible wavelength and the response time is about 5 ms. This typical sensitivity is related to the contribution of native point defects in electrical transport, as indicated by a space-charge-limited current regime. I-V curves in vacuum, Ar, and O2 environments reveal that oxygen vacancies (VO) play an important role in adsorption and desorption processes. Using absorption and temperature-dependent photoluminescence spectroscopy, the presence of VO is confirmed and dominates even at low temperature. The strong contribution of VO promotes low excitonic absorption, resulting in low photocurrent and fast-response detector. We propose that fast-response ZnO photodetector is not only originated from Schottky barrier but also from VO-related defect states. This result is important to improve the functionalities of ZnO for optoelectronic applications. |
| Databáze: | OpenAIRE |
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