ZnO quantum dot based thin films as promising electron transport layer: Influence of surface-to-volume ratio on the photoelectric properties

Nomaan, Ahlaam T.; Ahmed, Anas A.; Ahmed, Naser M.; Idris, Muhammad Idzdihar; Hashim, M.R.; Rashid, Marzaini

doi:10.1016/j.ceramint.2021.01.094

Cited by 27 publications

(11 citation statements)

References 64 publications

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“…Previous studies reported that the light-activation of ZnO QDs could produce various types of highly reactive species, including superoxide anion (O 2 – ), singlet oxygen ( 1 O 2 ), and hydroxyl radical ( · OH), due to its high surface-to-volume ratios and many oxygen vacancy defects. − To further investigate the antibacterial activity of ZnO QDs, different reactive species were measured using EPR. As shown in Figure C,D, the weak signals of DMPO-O 2 – and TEMP- 1 O 2 indicated that the ZnO QDs and zinc thiazole have no almost generation of O 2 – and 1 O 2 under light and dark conditions.…”

Section: Resultsmentioning

confidence: 99%

Visible-Light-Driven Zinc Oxide Quantum Dots for the Management of Bacterial Fruit Blotch Disease and the Improvement of Melon Seedlings Growth

Wang

Qian

Jiang

et al. 2023

J. Agric. Food Chem.

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Bacterial fruit blotch is one of the most destructing diseases of melon producing-regions. Here, zinc oxide quantum dots (ZnO QDs) were synthesized, and their antibacterial activity against Acidovorax citrulli was investigated. The results indicated that the obtained ZnO QDs displayed 5.7-fold higher antibacterial activity than a commercial Zn-based bactericide (zinc thiazole). Interestingly, the antibacterial activity of ZnO QDs irradiated with light was 1.8 times higher than that of the dark-treated group. It was because ZnO QDs could induce the generation of hydroxyl radicals and then up-regulate the expression of oxidative stressrelated genes, finally leading to the loss of cell membrane integrity. A pot experiment demonstrated that foliar application of ZnO QDs significantly reduced the bacterial fruit blotch disease incidence (32.0%). Furthermore, the supply of ZnO QDs could improve the growth of infected melon seedlings by activating the antioxidant defense system. This work provides a promising light-activated quantum-bactericide for the management of pathogenic bacterial infections in melon crop protection.

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Section: Resultsmentioning

confidence: 99%

Visible-Light-Driven Zinc Oxide Quantum Dots for the Management of Bacterial Fruit Blotch Disease and the Improvement of Melon Seedlings Growth

Wang

Qian

Jiang

et al. 2023

J. Agric. Food Chem.

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Section: Table 1 (A)mentioning

confidence: 60%

“…However, annealing the films at 400, 500 and 600 °C shows the excitonic absorption peak at 361, 365 and 368 nm. These absorption peaks are very close to the excitonic bulk of the ZnO, which is located at 373 nm[32].Figure 6(b) depicts the optical transmittance and reflectance spectra (inset Figure 5(b))of AZO/ITO films before and after annealing at various temperatures ranging from 400 -600 °C for 60 min. Similar optical characteristics of ZnO/ITO were observed in AZO/ITO thin films after annealing, in which transmittance value is influenced by annealing.…”

mentioning

confidence: 89%

Effect of Annealing on the Structural and Optical Properties of ZnO/ITO and AZO/ITO Thin Films Prepared by Sol-Gel Spin Coating

et al. 2022

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This paper aims to investigate the effect of annealing on the structural and optical properties of ZnO/ITO and AZO/ITO thin films. In the preparation of ZnO and AZO films, zinc acetate dehydrate (Zn(CH3COO)2.2H2O), ethanol, diethanolamine (DEA), and AlCl3 were used as a starting material, solvent, stabilizer, and dopant sources, respectively. Both ZnO and AZO films were fabricated on ITO (indium tin oxide) substrates using the spin coating technique at room temperature with a rotating speed of 3,000 rpm in 30 s. The films were heated at various temperatures in the temperature range of 400 - 600 °C for 60 min. The crystallite size of the film is calculated using Debye-Scherrer and Williamson-Hall Methods. Based on the UDM results, the crystallite size of ZnO/ITO and AZO/ITO films increases after annealing in comparison with the films before annealing. From the optical UV-Vis measurements, there was an increase in the transmittance value of the samples after annealing. The transmittance value of ZnO/ITO and AZO/ITO films increases from 40 % before annealing to approximately 80 and 90 %, respectively after annealing. The increase in the transmittance valued in both ZnO/ITO and AZO/ITO after annealing is mainly due to an improvement in the crystalline phase of these films. The band gap energy of ZnO and AZO films is reduced with increasing annealing temperatures, from 3.26 eV before annealing to 3.19 eV for ZnO and 3.23 eV for AZO films after annealing at 600 °C. HIGHLIGHTS The sol-gel spin coating method was used to study the effect of annealing on the structural and optical properties of ZnO/ITO and AZO/ITO films The transmittance valued in both ZnO/ITO and AZO/ITO after annealing increase as a result of an improvement in the crystalline phase of these films Reducing the amorphous phase and the increase of the crystallite size of the films are the main reason for narrowing the band gap energy of the ZnO/ITO and AZO/ITO films

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“…The obtained TiO 2 NPs synthesized at 200 and 300 • C having a size below 5 nm corresponded to the quantum dots structure [21,22]. The ImageJ software program analyzed the micrographs and estimated the average particle size [23].…”

Section: Resultsmentioning

confidence: 99%

Photovoltaic Performance of Spherical TiO2 Nanoparticles Derived from Titanium Hydroxide Ti(OH)4: Role of Annealing Varying Temperature

et al. 2022

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High-quality titanium dioxide (TiO2 or titania) nanoparticles (TiO2NPs) with tailored morphologies are desirable for efficient photovoltaic applications. In this view, some thin films containing spherical TiO2NPs were prepared on indium tin oxide (ITO) and silicon (Si) substrates from titanium hydroxide Ti(OH)4 using the unified sol-gel, spray and spin coating method followed by thermal annealing at different temperatures (in the range of 200–650 °C). Samples were characterized using various analytical tools to determine the influence of annealing temperatures on their structures, morphologies, and optical and photovoltaic characteristics. A field-emission scanning electron microscope (FESEM) and energy-filtered transmission electron microscopy (EFTEM) images of the annealed films displayed the existence of spherical TiO2NPs of average size in the range of 3.2 to 33.94 nm. XRD analysis of the films showed their amorphous nature with anatase and rutile phase. Optical UV-Vis spectral analysis of the annealed films exhibited a decrease in the bandgap energy from 3.84 to 3.24 eV with the corresponding increase of annealing temperature from 200 to 650 °C. The optimum films obtained at 500 and 600 °C were utilized as electron transport layers to fabricate the metal-insulator-semiconductor solar cells. The cells’ power conversion efficiency assembled with the spherical TiO2NPs-enclosed thin films annealed at 500 and 600 °C were 1.02 and 0.28%, respectively. Furthermore, it was shown that the overall properties and photovoltaic performance of the TiO2NPs-based thin films could be improved via thermal annealing.

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ZnO quantum dot based thin films as promising electron transport layer: Influence of surface-to-volume ratio on the photoelectric properties

Cited by 27 publications

References 64 publications

Visible-Light-Driven Zinc Oxide Quantum Dots for the Management of Bacterial Fruit Blotch Disease and the Improvement of Melon Seedlings Growth

Visible-Light-Driven Zinc Oxide Quantum Dots for the Management of Bacterial Fruit Blotch Disease and the Improvement of Melon Seedlings Growth

Effect of Annealing on the Structural and Optical Properties of ZnO/ITO and AZO/ITO Thin Films Prepared by Sol-Gel Spin Coating

Photovoltaic Performance of Spherical TiO2 Nanoparticles Derived from Titanium Hydroxide Ti(OH)4: Role of Annealing Varying Temperature

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