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p-type Ag-N dual acceptor doped ZnO thin films with long electrical stability were deposited by DC magnetron reactive co-sputtering technique. After deposition, the films were annealed at 400 °C for one hour in a nitrogen-controlled atmosphere. The deposited films were amorphous. However, after annealing, they crystallize in the typical hexagonal wurtzite structure of ZnO. The Ag-N dual acceptors were incorporated substitutionally in the structure of zinc oxide, and achieving that; the three samples presented the p-type conductivity in the ZnO. Initial electrical properties showed a low resistivity of from 1 to 10−3 Ω·cm, Hall mobility of tens cm2/V·s, and a hole concentration from 1017 to 1019 cm−3. The electrical stability analysis reveals that the p-type conductivity of the ZnO:Ag,N films is very stable and does not revert to n-type, even after 36 months of aging. These results reveal the feasibility of using these films for applications in short-wavelength or transparent optoelectronic devices. [ABSTRACT FROM AUTHOR]

The presented work shows the formation and profiling of nanocrystalline LiNbO3 films obtained by pulsed laser deposition, as well as the influence of the laser pulse repetition rate on the electrical properties, morphology, and growth processes of granular films. The study revealed that the nucleation process in LiNbO3 films can be intentionally altered by increasing the laser pulse repetition rate. When the repetition rate was set to 4 Hz, the resulting film comprised local islands and clusters with a diameter of 118.1 ± 5.9 nm. On the other hand, nanocrystalline films grown at a repetition rate of 10 Hz exhibited a continuous granular structure with a grain diameter of 235 ± 11.75 nm. These findings have the potential to contribute to the advancement of environmentally friendly energy devices utilizing lead-free piezoelectric energy harvesters. [ABSTRACT FROM AUTHOR]

A systematic study of growth, structural, electrical, and luminescence properties of zinc oxide (ZnO) layers grown on c-oriented GaN/sapphire templates by the pulsed laser deposition technique is carried out. A thorough high-resolution x-ray diffraction study reveals that c-ZnO films with high crystalline quality can be grown under certain growth conditions. Screw and edge dislocation densities in these films are found to be as low as 7 × 10 8 and 3 × 10 10 c m − 2 , respectively. All layers are found to be unintentionally n-type with ∼ 10 19 c m − 3 electron concentration and mobility as high as ∼50 cm2 V−1 s−1. Temperature and excitation intensity dependent photoluminescence (PL) studies as functions of the growth conditions are carried out to identify the transition processes behind various luminescence features found in these samples. At low temperatures, PL spectra are marked by sharp neutral donor bound excitonic transitions, their phonon replicas, and two broad luminescence bands at 2.2 and 2.9 eV. These broad bands are attributed to transitions from the (2+/0) oxygen vacancy (V O) and (2+/+/0) zinc-interstitial (Z n i) levels, respectively, to the valence band. Thermal energy needed to depopulate these defects is found to be 11 and 385 meV, respectively, for the (2+/0) V O and (2+/+/0) Z n i levels. Low temperature PL spectra for the samples grown with relatively high oxygen pressures are featured by the Zn-vacancy (V Zn ) related neutral acceptor bound excitonic transition, its phonon replicas, and a broad band at 2.75 eV. This band diminishes with increasing temperature and, instead, another broad feature appears at ∼2.1 eV. Our study attributes the 2.75 eV band to transition from the conduction band to (0/−) V Zn levels and the 2.1 eV feature to the transition between (−/2−) V Zn levels and the valence band. It has been found that all the defect related features can be minimized by adjusting the growth conditions. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) and ZnO-silver (ZnO-Ag) nanoparticles (NPs) are widely used in different fields, such as biomedicine and food packaging, due to their recognized antibacterial activity and safety for human health. In this paper, ZnO and ZnO-Ag NPs were incorporated into poly(butylene adipate-co-terephthalate) (PBAT), in two contents (0.5 and 1 wt%), to prepare antibacterial films. The NPs were characterized by TEM and FT-Raman, and the films were analyzed by FT-Raman and FTIR, mechanical properties, SEM–EDS, TGA, DSC, XRD, and antibacterial properties against Escherichia coli. The results indicate that both NPs were physically retained in the polymer structure, with a strong electrostatic interaction between the mixture components, reflecting excellent mechanical behavior. The films showed good thermal stability, without significant changes, and the nanocomposites enhanced PBAT crystallinity from 18 to 23% and 27% for PBAT-ZnO and PBAT-ZnO-Ag films, respectively. The mechanical, thermal, and crystallinity results indicated the excellent potential of NPs in biodegradable films to improve properties and expand applicability. The antimicrobial activity is higher for PBAT-ZnO-Ag films than the pristine PBAT due to the synergic effect between the NPs and the oxidation–reduction potential of each nanoparticle, where the ZnO protect and stabilized the Ag-NPs, acting as an Ag-carrier, enhancing its antimicrobial effects after the film's preparation and allowing its applicability in biomedical products or food packaging. [ABSTRACT FROM AUTHOR]

Nanostructured Wide Bandgap Semiconductors (NWBS) are supposed to be one of the candidate materials for manufacturing ultraviolet photodetectors (UVPDs) with excellent performance. Recently, different nanostructured ZnO was applied in UVPDs, which has been reported to possess outstanding advantages for UV detection and attract extensive research. Although some significant progress has been reported in the research of UVPDs, there are still other problems needs to be drawn more attention. For example, the electron depletion layer will be caused by the oxygen adsorption on the surface of ZnO, which could reduce the electron concentration. This review begins with machining methods of different nanostructured ZnO (e.g. ZnO nanowires (NWs), nanorods (NRs), microtubes, nanoparticles (NPs), nanoneedles and film) and then the detection mechanism of the UVPDs is also introduced. In addition, UVPDs assembled with core structure mentioned show different photoelectric properties in this review, mainly including responsivity, on/off ratio, and response time. Finally, the development trend of UVPDs research and its application prospect are prospected. [ABSTRACT FROM AUTHOR]

This article presents the results of experimental studies of the impact of electrode material and the effect of nanoscale film thickness on the resistive switching in forming-free nanocrystalline ZnO films grown by pulsed laser deposition. It was demonstrated that the nanocrystalline ZnO film with TiN, Pt, ZnO:In, and ZnO:Pd bottom electrodes exhibits a nonlinear bipolar effect of forming-free resistive switching. The sample with Pt showed the highest resistance values RHRS and RLRS and the highest value of Uset = 2.7 ± 0.4 V. The samples with the ZnO:In and ZnO:Pd bottom electrode showed the lowest Uset and Ures values. An increase in the number of laser pulses from 1000 to 5000 was shown to lead to an increase in the thickness of the nanocrystalline ZnO film from 7.2 ± 2.5 nm to 53.6 ± 18.3 nm. The dependence of electrophysical parameters (electron concentration, electron mobility, and resistivity) on the thickness of the forming-free nanocrystalline ZnO film for the TiN/ZnO/W structure was investigated. The endurance test and homogeneity test for TiN/ZnO/W structures were performed. The structure Al2O3/TiN/ZnO/W with a nanocrystalline ZnO thickness 41.2 ± 9.7 nm was shown to be preferable for the manufacture of ReRAM and memristive neuromorphic systems due to the highest value of RHRS/RLRS = 2307.8 ± 166.4 and low values of Uset = 1.9 ± 0.2 V and Ures = −1.3 ± 0.5 V. It was demonstrated that the use of the TiN top electrode in the Al2O3/TiN/ZnO memristor structure allowed for the reduction in Uset and Ures and the increase in the RHRS/RLRS ratio. The results obtained can be used in the manufacturing of resistive-switching nanoscale devices for neuromorphic computing based on the forming-free nanocrystalline ZnO oxide films. [ABSTRACT FROM AUTHOR]