In this paper, ultraviolet (UV) detection properties of epitaxial ZnO films grown on sapphire substrates with radio-frequency magnetron sputtering is reported. The responsivity (R) of the ZnO photoconductors measured at 325 nm wavelength shows a strong dependence on the incident power (P), i.e., R µ P-k (k = 0.7). A responsivity of 3500 A/W (or a gain of 6000) is obtained at the optical power density of 10-7 W/cm2, and the value decreases to 1 A/W at 10-2 W/cm2. The ultra-high responsivity at the low power regime suggests a long lifetime (order of 10 ms) of carriers. The enhanced carrier lifetime is explained by the preferential capture of holes at the recombination centers that exist in the depletion region around grain boundaries and film surface, and the subsequent separation of photogenerated carriers. The strong dependence of the responsivity on the incident power is attributed to the modulation of space charge region width by the photogenerated holes and the resulting change in carrier lifetime.
| Published in |
American Journal of Nano Research and Applications (Volume 7, Issue 1)
This article belongs to the Special Issue Recent Advances of Nanomaterials and Devices |
| DOI | 10.11648/j.nano.20190701.12 |
| Page(s) | 6-10 |
| Creative Commons |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited. |
| Copyright |
Copyright © The Author(s), 2019. Published by Science Publishing Group |
ZnO, High Responsivity, Epitaxial, UV, Photoconductor, GaN
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APA Style
Ahmed Mohammed Nahhas. (2019). High Responsivity Ultraviolet Photoconductors Based on Epitaxial ZnO Thin Films. American Journal of Nano Research and Applications, 7(1), 6-10. https://doi.org/10.11648/j.nano.20190701.12
ACS Style
Ahmed Mohammed Nahhas. High Responsivity Ultraviolet Photoconductors Based on Epitaxial ZnO Thin Films. Am. J. Nano Res. Appl. 2019, 7(1), 6-10. doi: 10.11648/j.nano.20190701.12
AMA Style
Ahmed Mohammed Nahhas. High Responsivity Ultraviolet Photoconductors Based on Epitaxial ZnO Thin Films. Am J Nano Res Appl. 2019;7(1):6-10. doi: 10.11648/j.nano.20190701.12
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Download@article{10.11648/j.nano.20190701.12,
author = {Ahmed Mohammed Nahhas},
title = {High Responsivity Ultraviolet Photoconductors Based on Epitaxial ZnO Thin Films},
journal = {American Journal of Nano Research and Applications},
volume = {7},
number = {1},
pages = {6-10},
doi = {10.11648/j.nano.20190701.12},
url = {https://doi.org/10.11648/j.nano.20190701.12},
eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.nano.20190701.12},
abstract = {In this paper, ultraviolet (UV) detection properties of epitaxial ZnO films grown on sapphire substrates with radio-frequency magnetron sputtering is reported. The responsivity (R) of the ZnO photoconductors measured at 325 nm wavelength shows a strong dependence on the incident power (P), i.e., R µ P-k (k = 0.7). A responsivity of 3500 A/W (or a gain of 6000) is obtained at the optical power density of 10-7 W/cm2, and the value decreases to 1 A/W at 10-2 W/cm2. The ultra-high responsivity at the low power regime suggests a long lifetime (order of 10 ms) of carriers. The enhanced carrier lifetime is explained by the preferential capture of holes at the recombination centers that exist in the depletion region around grain boundaries and film surface, and the subsequent separation of photogenerated carriers. The strong dependence of the responsivity on the incident power is attributed to the modulation of space charge region width by the photogenerated holes and the resulting change in carrier lifetime.},
year = {2019}
}
TY - JOUR T1 - High Responsivity Ultraviolet Photoconductors Based on Epitaxial ZnO Thin Films AU - Ahmed Mohammed Nahhas Y1 - 2019/09/02 PY - 2019 N1 - https://doi.org/10.11648/j.nano.20190701.12 DO - 10.11648/j.nano.20190701.12 T2 - American Journal of Nano Research and Applications JF - American Journal of Nano Research and Applications JO - American Journal of Nano Research and Applications SP - 6 EP - 10 PB - Science Publishing Group SN - 2575-3738 UR - https://doi.org/10.11648/j.nano.20190701.12 AB - In this paper, ultraviolet (UV) detection properties of epitaxial ZnO films grown on sapphire substrates with radio-frequency magnetron sputtering is reported. The responsivity (R) of the ZnO photoconductors measured at 325 nm wavelength shows a strong dependence on the incident power (P), i.e., R µ P-k (k = 0.7). A responsivity of 3500 A/W (or a gain of 6000) is obtained at the optical power density of 10-7 W/cm2, and the value decreases to 1 A/W at 10-2 W/cm2. The ultra-high responsivity at the low power regime suggests a long lifetime (order of 10 ms) of carriers. The enhanced carrier lifetime is explained by the preferential capture of holes at the recombination centers that exist in the depletion region around grain boundaries and film surface, and the subsequent separation of photogenerated carriers. The strong dependence of the responsivity on the incident power is attributed to the modulation of space charge region width by the photogenerated holes and the resulting change in carrier lifetime. VL - 7 IS - 1 ER -
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