Metal oxide semiconductors have attracted considerable attention due to their remarkable chemical, thermal, and electronic stability. In turn, there is an interest in developing flexible technology based on these materials; however, many of the substrates used are temperature sensitive. For flexible technology to succeed, low-temperature growth of semiconductor films is essential. In this work, NiOx thin films were deposited at room temperature under varying oxygen pressures using reactive pulsed laser deposition on glass substrates. The thin films, with an average thickness of 45 nm, were characterized in situ using X-ray photoelectron spectroscopy, which revealed the evolution of oxidation states and stoichiometry with increasing oxygen pressure. Furthermore, a p-n microdiode was fabricated via photolithography as proof that the NiOx produced through this methodology can be integrated into a device. The films were characterized as polycrystalline, presenting cubic structure. The refractive index exhibited a range from 2.29 to 1.92 at 632.8 nm. The electrical resistivity spanned from 53.5 to 4.88 ohm cm, the carrier density was around x 1018 cm-3. The I-V measurement of the microdiode revealed a forward voltage of 0.6 V. These results confirm the feasibility of room-temperature growth NiOx thin films for integration into functional flexible electronic devices.

A series of ZnO:N thin films were deposited by means of reactive pulsed laser deposition at room temperature on SiO2 glass slides, quartz, Al2O3, polyimide, silicon, and thermally oxidized SiO2. The p-type conductivity was confirmed by Hall effect-Van der Pauw measurements, with electrical parameters varying depending on the substrate deposition as follow: hole concentration between 2.4 x 1018- 3.8 x 1017 cm-3 , resistivity between 0.5 and 4 Omega cm, and mobility between 2 and 8 cm 2 V-1 s-1 . In situ X-ray photoelectron spectroscopy revealed identical binding energy values of the ZnO:N thin films across all substrates; the relative atomic concentrations varied between 49 and 53.8 at.%, 44-49 at.% and 2-2.4 at.% for zinc, oxygen and nitrogen respectively, due to over- quantification related to zinc particle splashing. Scanning electron microscopy confirmed a surface roughness of the films below 2 nm. Several wide and defect-related emissions were found by Cathodoluminescence; but the film deposited on quartz exhibited a unique, intense, and narrow blue band, the deconvolution of which revealed peaks at wavelengths of 430 nm and 461 nm. A growth rate of 14 nm/h, and an etching rate of 2 nm/s were found; these parameters were confirmed with the fabrication of smooth-walled ZnO:N thin films microstructures using photolithography. Finally, Thin Film Transistors (TFT) were fabricated. The devices exhibited low, but clear field effect current amplification, with a I on /I off = 10. The feasibility of using room-temperature deposited p-type ZnO:N thin films for p-channel TFT fabrication was demonstrated.

This work presents advances in developing photonic circuits, proposed on an integrated silicon nitride platform, for applications in quantum technologies. Among other functionalities, these devices are designed to generate and control quantum states of light.

This work studies nickel-cobalt oxide (NiCo2O4) thin films synthesized via chemical bath deposition for potential application as p-type active layers in electronic devices. X-ray photoemission electron spectroscopy (XPS) confirms the synthesis of a ternary compound with a stoichiometry of Ni1.04Co1.96O4. The thin film sample exhibiting the closest stoichiometry to the ternary compound has a thickness of approximately 50 nm. Scanning Electron Microscopy (SEM) micrographs indicate an increase in surface porous size corresponding to higher nickel concentrations in the ternary compound. All synthesized NiCo2O4 thin films demonstrate p-type behavior. The lowest resistivity film had a majority carrier concentration of 1x10(20) 1/cm(3), a mobility value of 0.1 cm(2)/Vs, and a resistivity of 0.1 Omega cm. X-ray diffraction (XRD) studies reveal that the thin films have a type of spinel cubic structure for the phase NiCo2O4. Characteristic spinel bands are observed in the UV-Vis transmittance spectra, and the energy bandgaps of the Ni1.04Co1.96O4 film are estimated to be approximately 3.41 and 2.19 eV using the Tauc method. The thin film with the lowest resistivity was used as an active layer to fabricate a thin-film transistor, displaying typical output curves of a p-channel transistor.

Silicon nitride has been used in the silicon photonics industry as an adequate alternative for manufacturing waveguides with good behavior for integrated nonlinear optics applications. In this work, we study the optical properties of silicon nitride thin films grown by the radiofrequency magnetron sputtering technique in a reactive process at room temperature. To determine the features of our material, we grow near to stoichiometric silicon nitride modifying several synthesis parameters, and we studied the variation of their linear and nonlinear properties. Employing the z-scan technique, we have found that our material’s nonlinear refractive index is about 1.04×10−15 m2/W, measured with femtosecond pulses centered at 0.8μm. We also studied the chemical composition through X-ray photoelectron spectroscopy and we confirm through X-ray diffraction that our thin films are not crystalline. The results suggest our material is a promising option for their use in nonlinear and quantum optics in integrated platforms.

Thermally processed nickel oxide (NiO) thin films were synthesized from nickel hydroxide films obtained by chemical solution deposition. Potential applications derived from electronic properties were studied by thermally treated thin films under two controlled annealing atmospheres. The NiO thin films with thicknesses between 160 and 192 nm and a nanowall-like morphology were obtained. Amorphous thin films with high optical trans-mittance in the visible region of around 85 % and similar to 3.7 eV bandgap energy were obtained. The chemical composition of the NiO films was determined by X-ray photoelectron spectroscopy (XPS), which confirmed that the films were indeed composed of NiO after thermal treatment. The electrical properties were acquired through the Hall effect technique. The NiO films exhibit a p-type conductivity; the highest carrier concentration is 5x10(15) cm(-3). Mobility up to 11 cm(2)center dot V-1 center dot S-1 and low resistivity of 9x10(2) Omega center dot cm. These properties are suitable for applications in transparent electronic devices.

The present work reports the analysis of the morphology, structure, optical properties, and photocatalytic performance of Selaginella lepidohylla-mediated ZnO nanoparticles (NPs). The ZnO NPs were obtained using varying concentrations of Selaginella lepidophylla as a chelating agent. The morphological analysis confirmed spherical shape and sizes of 19.86–27.75 nm for the obtained ZnO. The structural analysis revealed a hexagonal wurtzite phase and high crystallinity. Additionally, bandgap values of 2.7 eV to 2.9 eV were calculated through analysis of the optical properties. Elemental analysis identified the main Zn, O and C peaks, as well as oxygen vacancies in the ZnO lattice. The UV photocatalytic performance of the ZnO NPs was evaluated through the discoloration of RhB as a model organic pollutant. The ZD4 sample demonstrated the best results with 99.7

We present a design for an integrated single-qubit quantum gate based on the third order nonlinear process of difference frequency generation. A theoretical model is presented for the transformation of the qubit with device-external parameters.

Low temperature processing as well as long-term electrical stability are required to match p-type ZnO thin films with flexible electronics applications. Herein, ZnO and ZnO:N thin films were deposited at room temperature by reactive pulsed laser deposition of a zinc metallic target. Several ZnO thin films were obtained by varying the oxygen working pressure from 1.2 x 10(-5) Torr to 3.5 x 10(-2) Torr. Chemical concentration was smoothly tuned as demonstrated by in situ X-ray Photoelectron Spectroscopy. Introducing and varying both N-2 and O-2 fluxes at a constant pressure, N-doped ZnO films from 0.3 at.% to 5 at.% were deposited. Adjusting the N-2/O-2 flux ratio, ptype ZnO:N films were successfully achieved, exhibiting a carrier concentration of 5.3 x 10(18) cm(-3), resistivity of 2 Omega cm, and mobility of 0.5 cm(2)V(-1)s(- 1). Four representative p-type samples were analyzed to confirm chemical and electrical reproducibility. Electrical properties of one of these films were measured again nine months after deposited, and p-type conductivity was still observed. Cathodoluminescence revealed green-dominant emissions in n-ZnO and UV-dominant emissions in p-ZnO:N films as nitrogen doping effect. Finally, a p-n diode was fabricated using photolithography, exhibiting rectification performance even nine months after deposited. P-type ZnO:N presented here are suitable for flexible electronics devices fabrication.

In recent years, flexible electronics have been an area of considerable interest due to the development of materials such as transparent semiconductor oxides, which are compatible with flexible substrates. Herein, lithography and magnetron sputtering are used to fabricate a flexible p–n diode of SnOx thin films on a polyimide substrate and electrical characterization is performed by varying the bending cycles. Using specific oxygen concentrations in the reactive gas mixture of the sputtering system, transparent p‐SnO0.8 (8.0% ppO2) and n‐SnO1.2 (18.5% ppO2) on polyimide substrates are successfully deposited. Electrical results show the SnOx diode exhibits a threshold voltage of 2.24 V and a great rectification ratio of 102. It is found the diode has excellent I–V rectifying behavior even when subjected to bending with a radius of curvature of 10 mm. It is important to note that after 200 bending cycles at a curvature radius of 50 mm, the p‐SnOx/n‐SnOx diode retains its rectifying behavior, making it attractive for large‐scale applications in transparent and flexible electronics.

In this work, we report the influence of single-ionized oxygen vacancies ( V^'_O ) as a spin ½ system in the ferromagnetic response of undoped and Cr-doped SnO 2 nanowires. For this study, undoped and Cr-doped SnO 2 nanowires were synthesized by a thermal evaporation method. Raman, Auger, and X-ray photoelectron spectroscopies confirmed the incorporation of Cr 3+ ions in the SnO 2 lattice. Electron paramagnetic resonance measurements demonstrated the presence of single-ionized oxygen vacancies ( V^'_O ) in undoped and Cr-doped nanowires. Complementarily, cathodoluminescence measurements confirmed the presence of V O defects in the samples. Magnetic measurements revealed FM behavior from the undoped SnO 2 and Cr-doped SnO 2 nanowires, showing magnetization saturation values ( M S ) of ± 1 × 10 –3 and ± 1.6 × 10 –3 emu/g, respectively, and magnetic coercivity values ( H C ) of 180 and 200 Oe. We assign the FM response of nanowires to the presence of single ionized V^'_O acting as a spin ½ system and to the alignment of magnetic moments of Cr 3+ ions, finding that V^'_O defects dominate in the FM generation.

This work presents a feasible design of an integrated photonic circuit performing as a device for single-qubit preparation and rotations through the third-order nonlinear process of difference frequency generation (DFG) and defined in the temporal mode basis. The first stage of our circuit includes the generation of heralded single photons by spontaneous four-wave mixing in a micro-ring cavity engineered for delivering a single-photon state in a unique temporal mode. The second stage comprises the implementation of DFG in a spiral waveguide with controlled dispersion properties for reaching color qubit preparation fidelity close to unity. We present the generalized rotation operator related to the DFG process, a methodology for the device design, and qubit preparation fidelity results as a function of user-accessible parameters.

This study focused on the influence of the CH4/Ar flow ratio on the microstructure, chemical composition, morphology, and mechanical properties of TaCx coatings deposited on (1 1 1) silicon substrates using magnetron sputtering. To characterize the coatings, X-ray diffraction for the microstructural analysis, auger electron spectroscopy (AES) for the stoichiometry, a mechanical profilometer for roughness and thickness, and a nanoindenter for mechanical measurements were used. Two experiments were designed: the first consisted of producing TaCx coatings at room temperature (RT) using various CH4/Ar ratios, from 0.1 to 0.3, to identify the phases, stoichiometry, and hardness. These samples did not present crystalline phases and showed a transition from substoichiometric to over-stoichiometric materials. The over-stoichiometric coatings produced at CH4/Ar ratios greater than 0.2 exhibited a decrease in their hardness. For the second experiment, the substrate temperature was set at 500 degrees C to reach crystalline phases; the CH4/Ar ratio values were set to 0, 0.1, 0.125, 0.15, 0.175, and 0.2 to avoid over-stoichiometric coatings that exhibited lower hardness. At low CH4/Ar ratios, TaCx coatings were produced in an amorphous phase (alpha-Ta) and underwent a mixture of phases (alpha-Ta and cubic TaC). The materials tended to crystallize at CH4/Ar ratios greater than 0.175 (cubic TaC). All of the coatings were sub-stoichiometric, showing values from Ta to TaC0.56. Most of the samples exhibited a hardness of -30 GPa and a high Young's modulus, except for the coatings with the highest carbon concentration (TaC0.56). The Ta coatings exhibited the lowest roughness, although they had the highest thickness. This behavior was attributed to Ta exhibiting a higher deposition rate than TaC. In conclusion, the CH4/Ar ratio strongly influenced the crystallinity and stoichiometry of the coatings. Moreover, the materials exhibited a high hardness caused by their tendency to be amorphous.

In 2008, the alloy aluminum indium nitride, InAlN, was postulated as an excellent candidate to form high-efficiency solar cells. Therefore, the study of physical properties of this ternary alloy on transparent substrates is of paramount importance. In the present research, layers of different thickness of In0.63Al0.37 N were synthesized using the technique of DC magnetron sputtering on glass substrates. The thickness of the InAlN layers obtained was 37 nm, 80 nm, 130 nm, 235 nm and 320 nm. The structural and morphological analysis shows polycrystalline films whose grain size and roughness vary depending on the thickness of the layer. Measurements using Hall effect showed that the density of free carriers exhibits a behavior quite similar to grain size. In general, the behavior of the properties can be attributed to the polycrystalline structure of InxAl1-xN films, which represents an interesting aspect for its future use in solar cells.

Tin oxide (SnOx) has been widely used for the fabrication of transparent and flexible devices because of its excellent optical and electronic properties. In this work, we established a methodology for the synthesis of SnOx thin films with p‐type and n‐type tunable conductivity by direct currecnt (DC) magnetron sputtering. The SnOx thin films changed from p‐type to n‐type by increasing the relative oxygen partial pressure (ppO2) from 4.8% to 18.5% and by varying the working pressure between 1.8 and 2.5 mTorr. The SnOx thin films were annealed at 160°C, 180°C, and 200°C for 30 min to promote the formation of the desired crystalline structures. At the annealing temperature of 180°C in air ambient, the SnOx thin films showed a tetragonal structure with Sn traces. Having found the optimal conditions, we deposited both types of SnOx thin films with the same tetragonal structure and similar chemical stoichiometry. Also, the conditions to obtain thin films with the highest mobility values for p‐type (1.10 cm2/Vs) and n‐type (22.20 cm2/Vs) were used for fabricating the device. Finally, the implementation of a SnOx‐based p–n diode was demonstrated using transparent SnOx thin films developed in this work, illustrating their potential use in transparent electronics.

The semiconductor material of ternary alloy of Indium and Aluminum nitride (InxAl1-xN) has interesting properties for potential optoelectronic applications and solar cells as well. In the present research, layers of In0.63Al0.37 N were synthesized using the DC reactive sputtering magnetron technique, on p-type silicon substrates (100), ITO/PET, and ITO/Glass. The reason why an intermediate layer of ITO was placed on the PET and Glass substrates is that possibly in an InAlN thin-layer solar cell, the ITO would fulfill the role of Conductive Transparent Oxide (CTO). This CTO would be located between the window layer and the transparent substrate. On the other hand, in the case of a hetero-union solar cell, InAlN-n would be located on the Si-p material, in order to form the p–n junction. Therefore, the present work allowed us to study subsystems in which the InAlN would be part of the window layer in three different types of solar cells.

We report on thermally resilient planar waveguides fabricated on nc-YSZ by direct fs-laser inscription in transparent nc-yttria stabilized zirconia (nc-YSZ) polycrystalline ceramic. The waveguides consisted of rectangular sections (4.5 × 2 mm 2 ) on the surface of the sample. Optical characterization at 633 and 810 nm was performed. We estimate a laser-induced refractive index contrast of 10 –4 . Post-waveguide-fabrication thermal annealing treatments at 750°C for 24 h were carried out to test the resilience of the waveguides and to further reduce the waveguide losses. Both micro-Raman spectroscopy and XPS characterization revealed unmodified lattice and steady chemical features, which are consistent with the waveguide thermal resilience. Our results suggest a promising potential use of nc-YSZ in harsh and high temperature demanding photonic environments.

In this paper, the mechanical properties of TaNx/TaCx bilayers obtained by direct current magnetron sputtering are studied. The materials were manufactured by stacking bilayers formed by the periodic alternation TaN and TaC. Initially, samples of 40 bilayers were produced varying the deposition temperature (200, 300, 400 and 500 degrees C), finding the best mechanical properties for the sample grown at 500 degrees C; after that, the number of bilayers was varied, taking values of 10, 20, 40, 80 and 160. Transmission electron microscopy images show the layers formation and thicknesses between 1.2 and 1.6 mu m. In addition, X-ray diffraction patterns were acquired to observe the crystalline structure of samples produced varying the number of bilayers. Hardness was related to the preferential orientation and the competition between surface free energy and strain energy. The sample exhibiting the greatest hardness was obtained with 40 bilayers, in which, there is an equilibrium between both energies.

A proposal for the implementation of single-qubit quantum gates based on a third order nonlinear process in integrated quantum circuits is presented.