References of "Adjeroud, Noureddine"
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See detailControlling electrical and optical properties of zinc oxide thin films grown by thermal atomic layer deposition with oxygen gas
Nguyen, Tai; Adjeroud, Noureddine; Guennou, Mael UL et al

in Results in Materials (2020), 6

The preparation of ZnO thin films with controlled electrical resistivity and optical properties is often challenged by the presence of defects, such as oxygen vacancies or interstitial zinc. Here, we ... [more ▼]

The preparation of ZnO thin films with controlled electrical resistivity and optical properties is often challenged by the presence of defects, such as oxygen vacancies or interstitial zinc. Here, we investigate the material properties of ZnO polycrystalline thin films prepared by thermal Atomic Layer Deposition (ALD) with the presence of molecular oxygen pulsing during the growth. By means of structural, electrical and optical characterizations, we identify key growth parameters of this unusual ALD process. Unexpectedly, the influence of oxygen molecules on the crystallography, microstructure and morphology of ZnO films is significant from hundred-nanometers to micrometer thick film. The electrical resistivity of the films grown with oxygen gas shows a dramatic increase from 3 to 4 orders of magnitude. Additionally, photoluminescence measurements reveal that deep-level emissions caused by defects located deep in the band gap can be reduced by applying an adequate pulsing of oxygen gas during the process. Finally, we conclude with a discussion about the degree of consistency between the chemical composition, the inner strain and the optical and electrical properties of the films obtained with the different thermodynamic parameters of growth. Several hypotheses are discussed in order to understand the dominance of (002) orientation in the presence of oxygen during the ALD growth process. [less ▲]

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See detailMesoporous TiO2 anatase films for enhanced photocatalytic activity under UV and visible light
Ishchenko, Olga M.; Lamblin, Guillaume; Guillot, Jérôme et al

in RSC Adv. (2020), 10

Mesoporous TiO2 films with enhanced photocatalytic activity in both UV and visible wavelength ranges were developed through a non-conventional atomic layer deposition (ALD) process at room temperature ... [more ▼]

Mesoporous TiO2 films with enhanced photocatalytic activity in both UV and visible wavelength ranges were developed through a non-conventional atomic layer deposition (ALD) process at room temperature. Deposition at such a low temperature promotes the accumulation of by-products in the amorphous TiO2 films, caused by the incomplete hydrolysis of the TiCl4 precursor. The additional thermal annealing induces the fast recrystallisation of amorphous films, as well as an in situ acidic treatment of TiO2. The interplay between the deposition parameters, such as purge time, the amount of structural defects introduced and the enhancement of the photocatalytic properties from different mesoporous films clearly shows that our easily upscalable non-conventional ALD process is of great industrial interest for environmental remediation and other photocatalytic applications, such as hydrogen production. [less ▲]

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