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1 – 5 of 5Aminu Muhammad, Sabah M. Mohammad, Zainuriah Hassan, Suvindraj Rajamanickam, Shireen Mohammed Abed and M.G.B. Ashiq
The purpose of this study is to dope silver (Ag) and fluorine (F) in zinc oxide (ZnO) for the enhancement of electrical and optical properties of ZnO, as previous studies reported…
Abstract
Purpose
The purpose of this study is to dope silver (Ag) and fluorine (F) in zinc oxide (ZnO) for the enhancement of electrical and optical properties of ZnO, as previous studies reported the improvement of these properties using individual doping of F and Ag. In this paper, F and Ag co-doped ZnO nanorods were synthesized using a modified hydrothermal method.
Design/methodology/approach
The hydrothermal method was modified and used for the synthesis of the doped ZnO nanostructures, where stainless autoclave and oven were replaced with the Duran laboratory bottle and water boiler system in the process. The ultraviolet metal-semiconductor-metal photodetector (PD) was fabricated using DC sputtering method.
Findings
Vertically aligned nanorods images were captured from field emission scanning electron microscopy. XPS analysis confirmed greater spin-orbital interaction in the F and Ag co-doped ZnO sample and revealed the presence of F, Ag, Zn and O in the samples, indicating a successful doping process. X-ray diffraction revealed a hexagonal wurtzite structure with enhanced crystal quality upon co-doping. The bandgap decreased from 3.19 to 3.14 eV upon co-doping because of reduced defects density in the sample. Finally, an ultra-violet PD was fabricated with enhanced sensitivity and response times upon co-doping.
Originality/value
The low-cost, less energy-consuming Duran laboratory bottle and water boiler system were used as the substitute of expensive, more energy-consuming stainless autoclave and oven in a hydrothermal method for synthesis of F and Ag co-doped ZnO and subsequent fabrication of PD.
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Keywords
Shireen Mohammed Abed, Sabah M. Mohammad, Zainuriah Hassan, Aminu Muhammad and Suvindraj Rajamanickam
The purpose of this study is to fabricate an ultraviolet (UV) metal-semiconductor-metal (MSM) photodetector based on zinc oxide nanorods (ZnO NRs) grown on seeded silicon (Si…
Abstract
Purpose
The purpose of this study is to fabricate an ultraviolet (UV) metal-semiconductor-metal (MSM) photodetector based on zinc oxide nanorods (ZnO NRs) grown on seeded silicon (Si) substrate that was prepared by a low-cost method (drop-casting technique).
Design/methodology/approach
The drop-casting method was used for the seed layer deposition, the hydrothermal method was used for the growth of ZnO NRs and subsequent fabrication of UV MSM photodetector was done using the direct current sputtering technique. The performance of the fabricated MSM devices was investigated by current–voltage (I–V) measurements. The photodetection mechanism of the fabricated device was discussed.
Findings
Semi-vertically high-density ZnO (NRs) were effectively produced with a preferential orientation along the (002) direction, and increased crystallinity is confirmed by X-ray diffraction analysis. Photoluminescence results show a high UV region. The fabricated MSM UV photodetector showed that the ZnO (NRs) MSM device has great stability over time, high photocurrent, good sensitivity and high responsivity under 365 nm wavelength illumination and 0 V, 1 V, 2 V and 3 V applied bias. The responsivity and sensitivity for the fabricated ZnO NRs UV photodetector are 0.015 A W-1, 0.383 A W-1, 1.290 A W-1 and 1.982 A W-1 and 15,030, 42.639, 100.173 and 334.029, respectively, under UV light (365 nm) illumination at (0 V, 1 V, 2 V and 3 V).
Originality/value
This paper uses the drop-casting technique and the hydrothermal method as simple and low-cost methods to fabricate and improve the ZnO NRs photodetector.
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Srinivas Rao Sriram, Saidireddy Parne, Venkata Satya Chidambara Swamy Vaddadi, Damodar Edla, Nagaraju P., Raji Reddy Avala, Vijayakumar Yelsani and Uday Bhasker Sontu
This paper aims to focus on the basic principle of WO3 gas sensors to achieve high gas-sensing performance with good stability and repeatability. Metal oxide-based gas sensors are…
Abstract
Purpose
This paper aims to focus on the basic principle of WO3 gas sensors to achieve high gas-sensing performance with good stability and repeatability. Metal oxide-based gas sensors are widely used for monitoring toxic gas leakages in the environment, industries and households. For better livelihood and a healthy environment, it is extremely helpful to have sensors with higher accuracy and improved sensing features.
Design/methodology/approach
In the present review, the authors focus on recent synthesis methods of WO3-based gas sensors to enhance sensing features towards toxic gases.
Findings
This work has proved that the synthesis method led to provide different morphologies of nanostructured WO3-based material in turn to improve gas sensing performance along with its sensing mechanism.
Originality/value
In this work, the authors reviewed challenges and possibilities associated with the nanostructured WO3-based gas sensors to trace toxic gases such as ammonia, H2S and NO2 for future research.
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