Comparative investigation of Ga- and Sn-doped ZnO nanowires/p-Si heterojunctions for UV-photo sensing
29 Mar 2018-pp 1-5
TL;DR: In this paper, the photoresponse of the ZnO nanowire/p-Si heterojunction photodiodes was investigated by measuring the photo-to-dark current ratios, self-powered photo-switching behavior and intensity-dependant photocurrent at zero applied bias.
Abstract: Vertically oriented undoped, Ga-doped and Sn-doped ZnO nanowires are grown by using novel double step chemical bath deposition (CBD) technique. The nanowire morphology, crystallite quality, energy bandgap, and UV-visible absorption properties are investigated by employing FESEM, XRD and UV-vis measurements. Comparative photoresponse of the ZnO nanowire/p-Si heterojunction photodiodes is studied by measuring the photo-to-dark current ratios, self-powered photo-switching behavior and intensity-dependant photocurrent at zero applied bias. Ga-doped ZnO nanowires/p-Si heterojunction photodiode exhibits relatively higher photocurrent while the Sn-doped devices show faster photoswitching operation. An excellent photoresponse with the linear dependency of photocurrent on the incident UV-intensity has been observed in the Sn-doped photodiodes.
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17 Aug 2021
TL;DR: In this article, the effect of metal doping on ZnO nanoparticles for various applications such as solar cells, photocatalysis, medicines, light-emitting diodes, laser diode, chemical and biosensors is discussed.
Abstract: Nanosized ZnO-based materials for catalytic and sensing applications are highly proficient over bulk catalytic analogous due to higher surface and tunable physicochemical properties. The functionality, porosity, shape, size and surface area of these nanomaterials are crucial factors for influencing specificity and efficiency of its applications. In this review, we contemplated the effect of metal doping on ZnO nanoparticles for various applications such as solar cells, photocatalysis, medicines, light-emitting diodes, laser diodes, chemical and biosensors. The potential applications of metal-doped ZnO have gained significant attention owing to direct influence by the dopants on electronic and physiochemical properties. Especially, the natural bandgap (3.37 eV) and n-type conducting behaviour of ZnO can be tuned by doping of metals/metal oxides and non-metals by replacing Zn2+ and O2- in ZnO lattices respectively. Further, the bandgap modified ZnO could be used as a multi-functional material by growing it in various nanostructures such as bulk, thin layer and wires.
27 citations
TL;DR: In this paper, the effect of tin doping on structural ZnO thin films and optoelectrical features of photodiodes have been investigated, and the results showed that the tin doping improved the electrical and optical properties of the photodiode.
17 citations
References
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TL;DR: This article mainly concentrates on recent advances regarding the doping of ZnO one-dimensional nanostructures, including a brief overview of the vapor phase transport method and hydrothermal method, as well as the fabrication process for photodetectors.
Abstract: In the past decades, the doping of ZnO one-dimensional nanostructures has attracted a great deal of attention due to the variety of possible morphologies, large surface-to-volume ratios, simple and low cost processing, and excellent physical properties for fabricating high-performance electronic, magnetic, and optoelectronic devices. This article mainly concentrates on recent advances regarding the doping of ZnO one-dimensional nanostructures, including a brief overview of the vapor phase transport method and hydrothermal method, as well as the fabrication process for photodetectors. The dopant elements include B, Al, Ga, In, N, P, As, Sb, Ag, Cu, Ti, Na, K, Li, La, C, F, Cl, H, Mg, Mn, S, and Sn. The various dopants which act as acceptors or donors to realize either p-type or n-type are discussed. Doping to alter optical properties is also considered. Lastly, the perspectives and future research outlook of doped ZnO nanostructures are summarized.
161 citations
"Comparative investigation of Ga- an..." refers background in this paper
...One-dimensional binary metal oxide nanostructures have attracted a significant attention for the fabrication of various nanoscale devices such as photovoltaics, resistive memories, photoelectrochemical energy devices, gas sensors and photodetectors [1]....
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TL;DR: A graphene and zinc oxide nanowires based ultraviolet (UV) photodetector presents excellent responsivity and photocurrent gain with detectivity and suggests that the G/ZnO NWs device exhibits great promise for highly efficient UV photodETectors.
Abstract: A graphene and zinc oxide nanowires (G/ZnO NWs) based ultraviolet (UV) photodetector presents excellent responsivity and photocurrent gain with detectivity. Graphene due to higher charge carrier transport mobility induces faster response to UV illumination at the interface between ZnO and graphene with improved response and decay times as compared to a ZnO NWs device alone. A linear increase is revealed for both the responsivity and photocurrent gain of the G/ZnO NWs device with the applied bias. These results suggest that the G/ZnO NWs device exhibits great promise for highly efficient UV photodetectors.
77 citations
"Comparative investigation of Ga- an..." refers background in this paper
...Due to the high level of dark current and low photoresponse of the Si based photodetectors, the wide bandgap semiconductors are extensively being used for developing superior performance of UV photodetectors [2]....
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TL;DR: In this paper, Al-doped ZnO (AZO) nanosheets for a metal-semiconductor-metal ultraviolet (UV) photodetector (PD) were prepared.
Abstract: We demonstrated the fabrication of Al-doped ZnO (AZO) nanosheets on a glass substrate using the aqueous solution method. AZO nanosheets for a metal–semiconductor–metal ultraviolet (UV) photodetector (PD) were prepared. The average length and diameter of the AZO nanosheets were 1.44 μm and approximately 25 nm, respectively. The EDX spectrum of the Al-doped sample indicates that it contains approximately 0.64% at% Al. Our results show the high sensitivity of the UV PD, which reached 5.98 × 105. The measured transient response time and recovery time were 0.7 and 2.5 s, respectively.
45 citations
"Comparative investigation of Ga- an..." refers methods in this paper
...are used as dopants to tune the photoconductive properties [4-5]....
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TL;DR: In this paper, the UV sensing properties of Sn-doped and/or alloyed zinc oxide (ZnO) microstructures with different morphologies were investigated in order to elaborate the high performance UV photodetectors.
30 citations
TL;DR: In this article, a comparative performance analysis of ZnO nanowires grown by following single and double-step techniques on (100) p-Si substrate has been conducted, and the areal density of the double step approach is almost twice the nanowire grown by employing the single step approach.
Abstract: In this work, a comparative performance analysis of ZnO nanowires grown by following single- and double-step techniques on (100) p-Si substrate has been conducted. High-quality ZnO nanowires with c-axis orientation and perfect crystalline structures with appropriate chemical stoichiometry have been obtained from both the approaches. The areal density of the nanowires grown from double step approach is almost twice the nanowires grown by employing the single step approach. Histogram analysis shows that the diameter and height of majority of the single-step grown nanowires are ~370nm and ~2.45µm, and for the double step grown nanowires these are ~210 nm and ~2.16 µm, respectively. The bandgap values of the single-step and double-step grown nanowires are measured to 3.19eV and 3.26eV, respectively. The current-voltage characteristics of p-Si/n-ZnO diodes indicate that the forward current is contributed by both the electrons and holes and the relevant cut-in voltages are measured to be 0.5V and 2.5V, respectively. Copyright © 2016 VBRI Press.
19 citations