Al-Cr-Si-N coating: Substrate temperature effect on mechanical and scratch behaviour

In this research, nanocrystalline cadmium sulfide thin films were produced by the spray pyrolysis technique on glass substrates. The effects of substrate temperature in the range 400–550 °C on the structural, morphological, optical, and electrical properties of the thin films were investigated. The thin films have been characterized by investigating their X-ray diffraction, field emission scanning electron microscope (FE-SEM), and optical absorption (UV–Vis) measurements. X-ray analysis revealed that thin films were a polycrystalline structure with the hexagonal phase in all cases and by increasing in substrate temperature, crystallite size decreases, and dislocation density increases. The FE-SEM images showed that the surface of the thin films is uniform, homogeneous and without cracks. The average sizes of the grains are at the range of 210–235 nm. The obtained values for optical band gap have been in the range of 2.18–2.41 eV, where the value of optical band gap for the thin films decreases by increasing substrate temperature. The Urbach energies of the thin films increase as the substrate temperature is increased. When substrate temperature increased from 400 to 550 °C, electrical resistivity increased from 531 to 2817 Ω cm, carrier concentration decreased from 15.96 × 1014 to 3.71 × 1014 cm−3, Hall mobility decreased from 7.37 to 5.98 cm2/V s. Hall effect analysis indicated that the thin films exhibited n-type conductivity.

Undoped silicon thin films were deposited by a radio frequency plasma enhanced chemical vapor deposition technique over a wide range of substrate temperatures (170–370 °C) using a mixture of silane and hydrogen gas. A low power density (35 mW cm−2) was chosen. The effects of substrate temperature on the structural properties of the films was studied. A distinct transition from amorphous to microcrystalline phase is observed with an increase in the substrate temperature (Ts). Raman spectroscopy shows the variation of amorphous and crystalline volume fractions in the silicon films. The amorphous matrix seems to be composed mainly of monohydrides in contrast to the usual dominance of polyhydrides. At the onset of crystallinity, the films have tiny crystallites and the grain size (δ) increases with Ts (at Ts∼370 °C, δ∼350 Å). The deposition rate increases with Ts and attains its maximum (28.2 Å min−1) at the amorphous to microcrystalline transition region. All the microcrystalline films with their differing crystallinities degrade less than their amorphous counterparts under light exposure. The film prepared at the edge of crystallinity shows considerable photosensitivity (photogain of ∼103).

Transparent conducting CdO thin films were deposited on to glass substrates by spray pyrolysis technique. The depositions were carried out at different substrate temperatures with varying film thickness. The effects of substrate temperature on structural, optical and electrical properties of CdO thin films were systematically studied. The CdO films were polycrystalline in nature with cubic crystal structure showing preferential orientation along (111) direction. Wettability results confirmed that the hydrophobic character of CdO thin film is enhanced with increase in substrate temperatures. The average transmittance is about 80 %, thus the films are transparent in the visible region. The optical band gap value of the CdO films increased from 2.24 to 2.34 eV with increase in the substrate temperature from 200 to 350 °C. Surface morphology studies reveal that the grain size and roughness of the films are increased with increase in the substrate temperature. The minimum value of electrical resistivity of the films is 1.40 × 10−3 Ω cm obtained at 350 °C. The maximum ethanol sensitivity of 33.45 % is observed for the substrate temperature of 300 °C. Thus the results authenticate that the substrate temperature influences the structural, optical, electrical and sensing properties of the deposited films.

Using laser ablation technique carbon thin films were deposited on Si(100) substrate as a function of substrate temperature. In this study, the surface morphologic, structural and field emission properties of these carbon thin films were investigated using Raman spectroscopy, scanning electron microscopy, and a diode technique, respectively. With increasing of the substrate temperature, the surface morphologies were changed significantly. Moreover, the intensity of D-band and the full width at half maximum of these bands were dependent on substrate temperatures. As the substrate temperature was increased, the field emission properties were improved. As the result, we find that the field emission properties of the films were changed significantly with the substrate temperature and structural features of carbon than films.

Effect of substrate temperature on properties of multilayer thin film based on ZnO and Mo-doped indium oxide

We explored how tellurium (Te) anion distribution as a function of doping concentration and substrate temperature effects on the photovoltaic (PV) performance of narrow-bandgap Cu(In, Ga)Se2 thin film solar cells grown by a three-stage co-evaporation process. At low and moderate substrate temperatures (480 ℃ and 550 ℃), the inclusion of Te anions in the structure has negative impacts on photovoltaic parameters due to formation of disorder in the crystal structure, the deepening of the notch in the GGI gradient and the increase of defect-assisted recombination. At high substrate temperature (620 ℃), conversely, the presence of Te not only serves to improve the crystal structure and mitigate recombination through defect suppression but also facilitates the growth of large grains and attains a near-optimal GGI ratio (0.3) with a better gradient, which has a beneficial impact on the PV performance. These results highlight the role of Te anion distribution on PV performance of Cu(In, Ga)Se2 thin film solar cells and its potential for highly efficient commercial thin-film solar cells in reasonable and effective ways as a function of substrate temperature and doping concentration.

In this study, thin films of Gallium oxide nanoparticles were deposited using the method ‎of ‎pulsed laser deposition (PLD) on a glass substrate under different ‏substrate temperatures ‏‎(400, 500,‎‏ ‏and ‎‎600 K ) before and after annealing. The Nd-YAG laser was utilized at the wavelength ( 1064 nm ) and the ‎frequency ‎‎(5 Hz) at 130 0C. The effect of substrate temperature value before and after annealing on the Structural and morphological Properties was studied by UV-VIS, X-ray diffraction ‎‏)‏XRD), scanning ‎electron ‎microscopy(SEM) and Atomic force microscopy (AFM) . The outcomes XRD showed ‎that the ‎structure of Ga2O3 nanoparticles is a polycrystalline structure of the monoclinic type with ‎Prominent crystal orientations of (-401), (-202), (- 111 ), (111), and (-312)‎‏.‏‎ It is ‎according to JCPDS card No.‎‏00‏‎-041-1103. Crystallite size for complete models increased with the growth substrate temperature value before and after annealing. The results of (SEM) for gallium oxide nanoparticles prepared ‎with ‎different substrate temperatures (400, 500, and 600 k) before and ‎after ‎annealing showed that the films increase their homogeneity and the ‎voids ‎decrease with increasing temperatures. The energy band gap decreased with increasing substrate temperatures, and the ‎absorption ‎ edge was in the UV zone..

Effect of substrate temperature on the electrical and optical properties of reactively evaporated indium tin oxide films

Chromium oxide coatings are chemically inert, have high mechanical strength, hardness and good optical characteristics; therefore, they have been widely used in many applications including corrosion protection, wear resistance, electronics, and optics. Cr2O3 is well suited for wear resistance applications, as it is one of the hardest oxides with 29.5 GPa hardness. Several deposition techniques have been tried for making these coatings. Cr2O3 coating hardness can vary substantially due to compositional and microstructural variations, depending on the deposition method. Hardness of a plasma-sprayed Cr2O3 coating, 50 lm thick was about 14.7 GPa, while a 200 nm thick RF-sputtered chromium oxide coating, stoichiometrically close to Cr2O3, exhibited 30 GPa hardness combined with good scratch resistance. Even for the bulk Cr2O3, hardness values reported were from 9 GPa to 29.5 GPa. Hones et al. investigated a correlation between the hardness and the sputtering deposition parameters, i.e. oxygen partial pressure and substrate temperature, and found favorable deposition conditions with an oxygen partial pressure of about 15–20 % of the total sputtering gas pressure at substrate temperatures exceeding 500 K. Good coating adhesion is required for wear and corrosion resistance applications. Premature failure can occur for many reasons including coating delamination, cracking and plastic deformation. In addition to this, thin ceramic PVD coatings usually have columnar grain structure with micro cracks, pinholes, transient grain boundaries and often high throughcoating porosity, which all lead to accelerated pitting corrosion and failure at the coating/substrate interface, especially in hostile environments. On the other hand, several studies showed that coating thickness plays an important role in enhancing both PVD-coated tool cutting performance and resistance to abrasive and erosive wear. Graded systems have been employed to obtain thicker coatings without losing performance in terms of coating adhesion and toughness. It is likely that thicker coatings will improve corrosion resistance in aqueous environments by eliminating through-thickness pin-hole defects. Coating mechanical, adhesion and wear properties are strongly affected by microstructure. Interfaces with high adhesion are known to ensure prolonged coating life and good wear resistance. Sputtered coating microstructure and physical characteristics depend on the deposition parameters. Also, substrate surface conditions prior to deposition, characterized by surface roughness, stress and oxidation state, play an important role in controlling coating properties. In this paper SEM and TEM techniques were used to characterize thicker chromium oxide coating interfacial microstructure as a step towards developing a unique method for depositing thicker coatings with small grains, smooth surface and low residual stress.

This study aims to create cobalt oxide layers using the spray pyrolysis approach. During this process, a cobalt chloride (COCl2.6H2O) aqueous solution is sprayed onto preheated glass substrate at temperatures in the range of 250°C to 400°C. To evaluate and characterize the structural, optical, morphological, and electrical characteristics of the samples, several techniques were employed, including X-ray diffraction (XRD), scanning electron microscopy, optical absorption measurements, and the four-point probe process. Structural analysis of the X-ray diffraction displayed that Co3O4 developed in a controlled manner, forming a cubic structure. The films were found to grow preferentially along the (111) or (331) directions depending on the temperature of the substrate. Furthermore, (XRD) analysis clearly indicated that the average Co3O4 grain size increased with higher substrate temperatures. Observations of the surface morphology indicated some overgrowth of cobalt oxide clusters alongside the presence of nanocrystalline grains, and small spherical particles are well distributed at both substrate temperatures of 250°C and 400°C. Optical studies revealed direct bandgap values ranging from 1.46 to 2.05 eV. The highest conductivity measured was 1.29 S/cm at a temperature of 400 °C. It's observed that as the substrate temperature rises, the electric conductivity of the prepared samples also increases.

In this work, we present the substrate temperature induced change in the structural, optical, vibrational and luminescence properties of mixed NiO:WO3 (95:5) thin films deposited on glass substrates by rf magnetron sputtering technique. X-ray diffraction analysis revealed the onset of crystallization of the films occurred at 300 °C. The average optical transmittance of the films varied between 91 and 97 % in the visible region. The refractive index and extinction coefficient of films are found to decrease with increasing substrate temperature. It was observed that the dispersion data obeyed the single oscillator of the Wemple-DiDomenico model, from which the dielectric constants, ratio between free carrier density and free carrier effective mass, plasma frequency, oscillator energy, oscillator strength, and dispersion energy parameters of NiO:WO3 films were calculated and reported for the first time due to variation in substrate temperature during deposition by rf magnetron sputtering. The micro-Raman result shows two broad peaks corresponding to one-phonon LO mode at 570 cm−1 and two-phonon LO mode at 1,100 cm−1 due to the vibrations of Ni–O bonds and the peak found at 870 cm−1 belongs to the W–O mode. Room temperature photoluminescence (RTPL) study exhibits two characteristic emission peaks at 3.32 eV (374 nm) and 2.93 eV (423 nm), which corresponding to the transition of 3d8 Ni2+ ions. We have made an attempt to discuss and correlate these results with the light of possible mechanisms underlying the phenomena.

Influence of substrate temperature and oxygen pressure on the structural and optical properties of polycrystalline BaTiO3 thin films grown by PLD

Structural, electrical, and optical properties of F-doped SnO or SnO2 films prepared by RF reactive magnetron sputtering at different substrate temperatures and O2 fluxes

Nanocrystalline SiC films prepared by direct deposition of carbon and silicon ions

Effect of balanced and unbalanced magnetron sputtering processes on the properties of SnO2 thin films