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We demonstrate the synthesis of zinc oxide microshells by thermal evaporation of ZnO and Zn powders. X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) observations reveal that the products are ZnO microshells with hollow cores, of which the wall thickness is about several hundred nanometers. The possible growth process is discussed.

The capacitance and loss tangent of thermally evaporated zinc phthalocyanine, ZnPc, semiconducting thin films were measured in the temperature range of 180–430 K and frequency between 0.1 and 20 kHz. Aluminum and gold electrical contact electrodes were employed to sandwich ZnPc films. For both electrode types, the capacitance and loss tangent showed strong dependence on both temperature and frequency. Such dependence is related to the relevant temperature and frequency range under consideration. The capacitance has strong temperature dependence for T>240 K and frequency below 3 kHz, while it becomes a constant at higher frequencies and all temperatures. The loss tangent dependence on temperature is more evident at low frequencies and a minimum or an indication of a minimum was observed in tan δ versus f curves. Loss tangent variation with temperature was not monotonic for all frequencies. An anomaly (maximum) in tan δ was observed approximately between 300 and 360 K. This maximum was attributed to the presence of oxygen molecules in the sample and their subsequent exhaustion as the temperature is increased. The behavior of capacitance and loss tangent (for both Al and Au-electrodes) may be explained qualitatively and successfully in terms of an equivalent circuit model.

Indium oxide (In₂O₃) pyramidal nano and microstructures were prepared by a thermal evaporation and condensation method. The preannealing step affected the nanostructures morphologies and their sensing capability. The nanosize structures have been fabricated in nucleated preorganized situation. By changing from prepared sites to undesired sites, the morphology was deteriorated. The synthesized In₂O₃ structures were characterized by field emission scanning electron microscopy (FESEM) and the X-ray diffraction (XRD) measurements. The FESEM images showed that nanostructures with 100–250 nm in size were fabricated. The XRD patterns indicated that most of the samples are crystalline. Then, the fabricated structures were investigated for H₂S gas sensing. The nanocrystal pyramids were found to be sensitive to as low as 100 ppb of H₂S gas at room temperature and microcrystal ones to 300 ppb. The nanopyramids demonstrated that they were very sensitive to gas presence and their response and recovery time were in a few seconds.

We have grown orthorhombic barium disilicide (${\mathrm{\text{BaSi}}}_2$) thin-films on modified silicon (Si) substrates by a thermal evaporation method. The surface modification of Si substrate was performed by a metal-assisted chemical etching method. The effects of etching time $t_e$ on crystalline quality as well as optical and electrical properties of the ${\mathrm{\text{BaSi}}}_2$ films were investigated. The obtained results showed that substrate modification can enhance the crystalline quality and electrical properties; reduce the light reflection; and increase the absorption of the ${\mathrm{\text{BaSi}}}_2$ thin-films. The $t_e$ of 8 s was chosen as the optimized condition for surface modification of Si substrate. The achieved inferred short-circuit current density, Hall mobility, and minority carrier lifetime of the ${\mathrm{\text{BaSi}}}_2$ film at $t_e$ of 8 s were $38{\mathrm{\text{mA/cm}}}^2$, $273{\mathrm{\text{cm}}}^2/\mathrm{\text{Vs}}$, and $2.3\mu$s, respectively. These results confirm that the ${\mathrm{\text{BaSi}}}_2$ thin-film evaporated on the modified Si substrate is a promising absorber for thin-film solar cell applications.

ZnS nanowires films were grown on two different substrates silicon and glass, with PbS dopant at 5 wt.%, using thermal evaporation method. The silicon is single crystal (only Si), while the glass is as amorphous substrate (mainly SiO₂). In the used substrates, the morphology was confirmed by Atomic Force Microscopy (AFM) as well as Scanning Electron Microscopy (SEM) images (cross-section and surface). High Resolution Transmission Electron Microscopy (HRTEM) has been used to confirm the ZnO nanowires for doped films (PbS:ZnS) in both silicon and glass substrates, with diameter less than 50 nm and the thickness was varied from 2000 nm to 3000 nm. The undoped film has dense structure and is thin with thickness of 200 nm. The growth of nanowires is not affected by the two substrate types (silicon and glass). The compositions of chemical films have been verified by energy dispersive X-ray spectroscopy (EDX), and it confirms that ZnS is the main compound. X-ray Diffraction (XRD) investigated the crystallographic properties with wurtzite structure. Optical properties (transparency and bandgap) were deduced from UltraViolet Visible (UV-Vis) spectra of ZnS films (PbS 0 and 5 wt.%) deposited on glass substrate. Raman, Photoluminescence (PL) and Fourier transform infrared (FTIR) techniques confirm ZnS composition and its nonstructural growth. Finally, a good agreement between the XRD, FTIR and HRTEM analyses was found.

The photoelectric properties of ZnO-doped WSe₂ thin films created on Si substrates by a thermal evaporation method were investigated. The effects of ZnO on the surface morphology, structure, photoluminescence, light absorption characteristics and electrical properties of WSe₂ thin films were analyzed. It is found that the nucleation density and the crystallinity of the ZnO-doped WSe₂ nanowires are higher than without doping, and the electron mobility of the doped sample is about 1.4 times that of the undoped sample. Also, doping improved the light absorption and photoluminescence efficiency. Additionally, the $I$–$V$ curve of the ZnO-doped WSe₂/Si heterojunction gradually changes from a rectification characteristic to a linear dependence, and the photocurrent increases by about four times when the light power increases from 0 to 25 mW/cm². Moreover, the heterojunction has a very high sensitivity to operating temperature; the current significantly increases as the temperature increases to $300^{\circ }$. With high absorptivity and photoluminescence efficiency, and sensitivity to light and temperature, ZnO-doped WSe₂ film is promising for use in optoelectronic devices.

Dye-sensitized solar cells (DSSCs) continue to attract as one of the most important renewable energy technologies due to their simple production, environmentally friendly, and lower-cost fabrication process compared to the most common types of solar cells. Zinc oxide (ZnO) nanostructures have motivated researchers to fabricate DSSCs as photo-anodes due to their unique properties, such as different types of structures, appropriate optical properties, proper energy bandgap, and high electron transfer characteristics. This article reports the simple preparation of ZnO tetrapod-like nanorods using the wet thermal evaporation method on porous silicon substrate PS/Si and applied as a photoanode on DSSCs. ZnO nanostructures were characterized by using grazing-angle X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) measurements. A significant difference in the performance of DSSCs has been investigated by using a standard dye di-tetrabutylammonium cis–bis(isothiocyanate)bis(2,2${}^{\prime }$-bipyridyl-4,4${}^{\prime }$-dicarboxylato) ruthenium (II) (N719) reloaded on ZnO tetrapod-like nanorods ($J_{\mathrm{\text{sc}}}=3.33$, $V_{\mathrm{\text{oc}}}=0.88$, $\mathrm{\text{FF}}=51$%, and $\eta =1.51$%) being more efficient than the ZnO spherical nanoparticles as a reference solar cell ($J_{\mathrm{\text{sc}}}=2.01$, $V_{\mathrm{\text{oc}}}=0.86$, $\mathrm{\text{FF}}=49$%, and $\eta =0.89$%).

In this paper, ZnO nanostructures have been synthesized by thermal evaporation process using metallic zinc powder in the presence of oxygen on $p$-Si (100) at different distances from the boat. The structural and optical characterizations have been carried out. The morphological study shows various shape nanostructures. XRD data indicate that all samples have a polycrystalline wurtzite hexagonal structure in such a way that the closer sample has a preferred orientation along (101) while the ones farther are grown along (002) direction. From the structural and optical data analysis, we found that the induced strains are the main parameter controlling the UV/green peaks ratios in the PL spectra of the studied samples.

In this study, structural properties of the Zn–In–Se (ZIS) thin films deposited by thermal evaporation method were investigated. The as-grown and annealed ZIS films were found in polycrystalline structure with the main orientation in (112) direction. The compositional analysis of the films showed that they were in Zn-rich behavior and there was a slight change in the elemental contribution to the structure with annealing process. Raman analysis was carried out to determine the crystalline structure and the different vibration modes of ZIS thin films. According to these measurements, the highest Raman intensity was in the LO mode which was directly proportional to the crystallinity of the samples. The atomic force microscopy (AFM) analyses were done in order to obtain detailed information about the morphology of the thin film surface. The surface of the films was observed as nearly-smooth and uniform in as-grown and annealed forms. X-ray photoelectron spectroscopy (XPS) measurements were analyzed to get detailed information about surface and near-surface characteristics of the films. The results from the surface and depth compositional analyses of the films showed quite good agreement with the energy dispersive X-ray spectroscopy (EDS) analysis.

The Er-doped ${\mathrm{\text{Ge}}}_{1-x}{\mathrm{\text{Sn}}}_x$ thin films with different Sn contents were prepared on Ge buffered Si substrates by thermal evaporation. The effect of Er doping on the crystallization of ${\mathrm{\text{Ge}}}_{1-x}{\mathrm{\text{Sn}}}_x$ films at different annealing temperatures was studied. It is demonstrated that Er doping can increase the critical crystallization temperature and greatly reduce the surface roughness of high temperature annealed ${\mathrm{\text{Ge}}}_{1-x}{\mathrm{\text{Sn}}}_x$ thin films.

Transparent conductive oxide (TCO) thin films are highly sought-after for their unique characteristics of conducting electricity and transmitting visible light, making them ideal conductive coating materials for electronic devices. We carried out a comprehensive analysis of the deposition, optical, electrical, and structural properties of ITO and Ag/ITO thin films on glass substrates in this study. The weight ratio of the deposited metals was 1:10, 2:10, and 4:10wt.% (Sn:In) for ITO films and 1:1:10wt.% (Ag:Sn:In) for Ag–ITO film. The films were annealed at 300°C using a program controller furnace. We employed infrared cameras to analyze the surface temperature profiles of these thin films under external voltage supply. We also investigated the resistivity behavior of both ITO and Ag–ITO films, analyzing them with regard to Mott’s variable range hopping (VRH) model and the fluctuation-induced tunneling model. Scanning electron microscope images revealed that adding Ag increased the grain size of ITO thin films. The average grain size for ITO thin film was determined as 186nm, while it was found to be 270nm for Ag–ITO thin film. Furthermore, incorporating Ag into the ITO thin film resulted in a reduction of 21.5% in transmittance over the complete visible range of the electromagnetic spectrum when compared to the ITO thin film without Ag as measured by ultra-visible spectrophotometer. The figure of merit was obtained as $0.344\times 10^{-3}{\mathrm{\Omega }}^{-1}$ for ITO and $0.0524\times 10^{-3}{\mathrm{\Omega }}^{-1}$ for Ag–ITO thin films. However, the resistance of the ITO thin film was calculated to be 9.58k$\mathrm{\Omega }$, while that of the Ag–ITO film was found to be 6.99k$\mathrm{\Omega }$. The ITO thin film that included Ag exhibited a lower electrical resistivity due to the larger grain size caused by doped Ag atoms in the structure, leading to less electron scattering at the grain boundaries and a resulting decrease in resistivity as determined by four-point probe system. Thermal imaging camera measurements revealed that the surface temperature of the ITO thin film decreased with the addition of Ag under high voltage application, but not under low voltage. When a voltage of 350V and 250V was applied to the thin films, the ITO film exhibited a surface temperature of 73.9°C and 50.4°C, whereas under identical conditions, the Ag–ITO film showed a surface temperature of 62°C and 44.1°C, respectively. Furthermore, both films exhibited exponentially increasing surface temperature behavior under a certain voltage, suggesting that they have potential for transparent heaters and high-voltage/low-current applications.

This work indicates the device properties of polycrystalline p-AgGaInTe₂ (AGIT) thin films deposited on bare and ITO-coated glass substrates with thermal evaporation technique. Device characteristics of n-CdS/p-AGIT heterostructure have been analyzed in terms of current–voltage ($I$–$V$) for different temperatures and capacitance–voltage ($C$–$V$) measurements for different frequencies, respectively. The series and shunt resistances were determined from the analysis of parasitic resistance for high forward and reverse bias voltages, respectively. The ideality factors were evaluated from $I$–$V$ variation at each sample temperature as lying in between 2.51 and 3.25. The barrier height was around 0.79eV at room temperature. For low bias region, the variation in the diode parameters due to the sample temperature exhibited the thermionic emission with $T_0$ anomaly, whereas space-charge-limited current analysis was also found to be pre-dominant carrier transport mechanism for this heterostructure. From $C$–$V$ measurements, the obtained built-in potential and series resistances were found to be in good agreement with $I$–$V$ results.

Raman spectrum has been used to analyze the size of Silicon (Si) quantum dots (QDs) prepared by thermal evaporation. Si QDs were grown in thermal evaporation chamber with Ar gas presented. We determined the average size of the Si QDs by analyzing the optical phonon of Si QDs in Raman spectra. We found that the higher the Ar gas pressure in the chamber, the larger the average size of Si QDs grown by thermal evaporation. We found the Si dot size reaches a maximum, about 7.5 nm in diameter, when Ar gas pressure is about 2–3 torr. The oxidization of Si QDs is also observed by Raman spectra. The life time of oxidized process was about 46 days.

Nanoparticle Lead sulfide was synthesized via simple chemical method and deposited on glass substrates at different substrate temperatures by thermal evaporation technique. The synthesized nanoparticle PbS was analyzed and confirmed by X-ray diffraction (XRD), Scanning electron microscopy SEM with EDX and thermogravimetry. The structural, optical, morphological and electrical properties of the deposited films were studied using XRD, UV-Vis, Raman, SEM with EDX, atomicforce microscopy AFM and Hall Effect measurements. The thickness of the deposited samples was measured using thickness profilometer. The Raman shift in the peak occurs toward lower energy with increasing substrate temperature deposited lead sulfide. The Z-scan study with open aperture was carried out at 532 nm using 5 ns laser pulse on the deposited films which shows that nonlinear absorption arises from saturable absorption process. The deposited PbS film exhibits p-type conductivity in Hall measurement.

The aim of this work is to fabricate high-crystalline nanoporous zinc oxide (ZnO) thin films by a modified thermal evaporation system. First, zinc thin films have been deposited on bare glass substrate by the modified thermal evaporation system with pressure of 0.05mbar, source–substrate distance of 3cm and source temperature 700${}^{\circ }$C. Then, high-crystalline ZnO thin film is obtained by annealing at 500${}^{\circ }$C for 2h in atmosphere. The prepared ZnO films are characterized with various deposition times of 10min and 20min. The structural property was investigated by X-ray diffractometer (XRD). The optical bandgap and absorbance/transmittance of these films are examined by ultraviolet/visible spectrophotometer. The surface morphological property has been observed by scanning electron microscope (SEM). ZnO films have showed uniform nanoporous surface with high-crystalline hexagonal wurtzite structure. The ZnO films prepared with 20min has excitation absorption-edge at 369nm, which is blueshifted with respect to the bulk absorption-edge appearing at 380nm. The gap energy of ZnO film is decreased from 3.14eV to 3.09eV with increase of the deposition time, which can enhance the excitation of ZnO films by the near visible light, and is suitable for the application of photocatalyst of waste water cleaning and polluted air purification.

Tin sulfide (SnS) is a promising material for solar cell absorber layer applications due to its low cost, ease of availability and lower toxicity than other semiconductor materials, used for the same purpose. Thermal evaporation was used to deposit thin-film solar cells with SnS on glass and silicon substrates, with minimal silver doping ratios (0.02, 0.04 and 0.06) wt.% and thickness in the 125-nm range. Surface morphology, crystallite size and optical and electrical characteristics have all been thoroughly investigated. XRD analysis revealed that /both the undoped and Ag-doped SnS films were well crystallized, with an orthorhombic structure and polycrystalline nature. The (111) plane was the preferred orientation. Due to the low doping ratios, there are no silver-specific peaks. Additionally, the Scherer formula was used to calculate the crystallite size, which showed an increase from 3.7096 to 10.4716nm. AFM images showed that SnS: Ag (6wt.%) film has bigger grains than other samples. The Hall Effect test revealed that the film is p-type conductivity. The optical bandgap values were found to be in the (2.6–1.7eV) range. All of the SnS films had an absorption coefficient of more than $105{\mathrm{\text{cm}}}^{-1}$ above the fundamental absorption edge. These polycrystalline and highly absorbing SnS thin films can be used to make heterojunction solar cells. The wider energy gap of the produced films, which allows more light to reach the solar cell junction, was found to be connected to changes in thin film microstructure characteristics. The efficiency of the prepared solar cells reached 5.4% for the 6wt.%Ag-doped SnS/Si solar cell, with a fill factor of 0.46.

The opto-electronic characteristics of porphyrin-fullerene bulk heterojunction photovoltaic cells of different active layer thicknesses were studied. In order to achieve different active layer thicknesses, the photovoltaic cells were prepared by spin coating the active layer of each cell at a different spin speed. To determine the active layer thickness, average of absorption coefficients of the materials constituting the active layer was used along with the optical density. Active layer thicknesses were also measured by using surface profilometer. Atomic force microscope surface scans revealed that there was no considerable change in active layer surface roughness from 1000 to 1500 rpm. However, a decrease in average grain size with increasing spin speed was observed. Current density as a function of voltage curves at different active layer thicknesses were recorded in dark and under a simulated solar spectrum AM 1.5G (100 mW.cm^-2). Incident photon-to-current conversion efficiency spectra at different active layer thicknesses were also determined. The solar cell having active layer thickness of 68 nm (spin coated at 1200 rpm) showed optimum results. The power conversion efficiency of the photovoltaic cell at this thickness was 0.24%.

Silver nanoparticles (NPs) films with different nominal thicknesses were deposited on the anodic aluminum oxide (AAO) templates with pore diameter about 200 nm by thermal evaporation. These NPs films were used as the surface enhanced Raman scattering (SERS) active substrates. The microstructure and surface morphology of the films were studied by X-ray diffraction and scanning electron microscopy, respectively. The SERS activity of the films was investigated by Raman scattering of adsorbed rhodamine 6G (R6G) at different concentrations. The results revealed that the average diameter of Ag NPs in different samples is 58 nm, 75 nm, 93 nm and 108 nm, respectively. Ag NPs film on AAO template is very suitable as a SERS active substrate and can detect R6G molecules with a concentration of 10^-8 M. The intensity of the SERS spectra is related to both the Ag NPs size and interparticle distance. The sample with an average particle diameter of 93 nm has the highest SERS enhancement factor (1.3 × 10⁶).

CuO:Cu₂O/Si heterojunctions have been prepared with different concentrations of Cu₂O nanoparticles using the thermal evaporation technique. The X-ray diffraction (XRD) results show that the prepared films are polycrystalline with orthorhombic structure and preferential orientation (110) direction along the $c$ axis at $2𝜃=32.82^{\circ }$, which corresponds to the pure CuO with crystallite size 18nm, while the particle size ranged from 14nm to 34 nm (resulted from SEM test). The optical properties were studied by recording the absorbance spectra using the UV–visible spectrophotometer. The absorbance increased with Cu₂O doping. The high values of the energy gap refer to the quantization effect. The electrical properties including the Hall effect were studied. CuO:Cu₂O/Si heterojunctions have been prepared at different concentrations. $I$–$V$ characteristics show that the Cu₂O doping increases the energy conversion efficiency by retarding the electron–hole recombination and the improved device performance is caused by the high short-circuit current ($I_{\mathrm{\text{sc}}})$ and open circuit voltage ($V_{\mathrm{\text{oc}}})$ and found that the highest efficiency ($\eta )$ at doping 0.006 Cu₂O 3.471% with $V_{\mathrm{\text{oc}}}$ of 2.20V, $I_{\mathrm{\text{sc}}}$ of 0.0170mA cm${}^{-2}$ and F.F of 0.6497 at $P=100$mW/cm².