E-beam Evaporation Technique Research Articles

Design, Fabrication and Characterization of n-Si Columnar Structures for Solar Cell Applications

Background: Glancing Angle Deposition (GLAD) provides oblique deposition and substrate motion to engineer thin film microstructures in three dimensions on nano scale. Using this technique zigzag, chevrons, staircase, post, helical and various type of nanostructures including 3-D multilayers can be obtained from various metals with controllable morphologies. The aim of the study is to increase surface porosity and junction using GLAD method area for thin film solar cells and therefore to increase p-n junction area. This provides efficient charge separation and strong light absorption. Methods: Glancing angle deposition using e-beam evaporation technique has been employed to create 3- D silicon nano-structures on the surface. Al and Ag contact layers were deposited by thermal evaporation technique. Hole-conductor polymer PEDOT: PSS was spin coated onto n type silicon thin film. Reflectance spectra were measured using UV-VIS spectroscopy. Scanning electron microscopy was used to image surface and cross-section with and without PEDOT: PSS. Also, transmission spectra of PEDOT: PSS was measured using UV-VIS spectroscopy. Surface wettability properties and contact angles of silicon samples were measured by contact angle measurement with water. Results: Columnar structures possess less reflection compared to the flat surface depending on surface porosity. This phenomenon shows that these structures can be used as anti-reflection coatings for solar cells and optical devices to decrease reflectivity and increase light harvesting with higher efficiency. Contact angle decreases when surface roughness increases therefore we can see that columnar structures are more hydrophilic compared to dense films. Flat silicon has 98° contact angle while columnar structures have 71° and 61°. PEDOT: PSS exhibits high transparency in the range from 200 to 1100 nm of wavelength of light, which resembles to solar radiation inside the atmosphere. Also, SEM images of the samples show that silicon columnar structures form better contact with PEDOT: PSS than flat surface. Conclusion: GLAD technique has been used to achieve homogenous rough surface by e-beam evaporation. Both cross-sectional and top-view SEM images show that columnar structures have higher porosity than flat surfaces. The response of UV-VIS spectroscopy shows that columnar structures have less reflection due to highly porous surface. With increasing incident flux angle, antireflection property of the surfaces was enhanced by surpassing the surface reflection. Due to the reduced hydrophobicity of porous structures, organic polymer can be distributed homogenously in between the columnar structures with increased p-n junction interface area. PEDOT: PSS is highly conductive, and it is highly transparent material in the range of the wavelength typically seen in the solar radiation. This makes it easier for light to reach to Si interface to generate electrons and holes. These results provide better understanding of Si- based heterojunction solar cells efficiency improvement with surface modification. This study also shows dependency of optical and electrical activity to surface geometry and surface porosity.

Отрицательная дифференциальная проводимость структур на основе оксида лантана

Using e-beam evaporation technique, transparent surface-hydrated lanthanum oxide (OH-La2O3) films with a thickness of 40, 140, and 545 nm were obtained. The electrical and optical characteristics of Al/OH-La2O3/p-Si structures were studied, where aluminum and a silicon substrate with p-type conductivity were used as the upper and lower electrodes, respectively. Negative differential conductivity region in the conductivity–voltage characteristics for the forward bias voltage was found; a possible mechanism of negative differential conductivity is explained by proton transport in hydrogen bonded chains of water molecules at the OH-La2O3 film surface.

High performance room temperature p-type injection in few-layered tungsten diselenide films from cobalt and palladium contacts

Field-effect electronic devices based on transition metals dichalcogenides (TMDs) have recently received a tremendous interest. Although widely studied, efficient charge injection in those materials is often impeded by the large injection barrier present at the interface between the electrode and the TMD, in particular when holes transport is needed. In this paper, e-beam lithography and e-beam evaporation techniques are used to contact few-layered WSe2 films with patterned metallic electrodes (Co and Pd).. We measured the transport and the injection properties at various gate voltages, source-drain voltages and different temperatures. A quantitative analysis is performed using a two-dimensional version of a thermionic emission model to extract the evolution of the injection barrier height as a function of the gate voltage. Palladium contacts are found to be very transparent in the hole injection regime but weakly tunable under the application of a gate voltage. Cobalt contacts present a low injection barrier which, unlike Pd contacts, can be extremely reduced by electrostatic gating. In both cases low injection barriers with respect to the literature are extracted. These results demonstrate a solid potential for applications implying WSe2 in the hole transport regime. The results reveal also an excellent agreement when compared to previous theoretical studies by taking into account the role of hybridized interfacial states and of the spin–orbit coupling of the contacting material on the injection barrier.

Thermal annealing induced physical properties of ZnSe thin films for buffer layer in solar cells

Abstract This article is dedicated to the study on the influence of thermal annealing on the physical properties of ZnSe thin films in order to seek a suitable alternative Cd-free window layer for developing high efficiency CdTe and CIGS solar cells. ZnSe films having thickness 300 nm were deposited onto glass and ITO substrates employing e-beam evaporation technique and then thermal annealing was undertaken in temperature range of 373–573 K with an interval of 100 K. The structural studies show that films are having cubic phase with (111) predominant peak and grain size corresponding to the preferred peak is observed to vary with annealing. The optical parameters like absorbance, transmittance, extinction coefficient, refractive index were also evaluated. The transmittance of films is found to vary and 573 K annealed films have shown maximum transmittance. The optical energy band gap was found to increase with annealing from 1.97 eV to 2.47 eV. Electrical analysis revealed the linear relationship between current and voltage indicating ohmic nature of the contacts. The results are also correlated with the surface morphology of the thin ZnSe films while the presence of Zn and Se peaks in EDAX spectra confirmed the film deposition.

Optical and electrical properties of a-AgSbS1.5Se0.5 chalcogenide thin films

AgSbS1.5Se0.5 films were deposited by e-beam evaporation technique onto clean glass substrates. The structural characterization of the deposited film was conducted using X-ray and transmission electron microscope techniques. The atomic percent of the constituent elements of the deposited films was investigated using energy dispersive X-ray spectrometry. The effect of thermal annealing on the structural and the optical properties of the deposited films has been studied. The transmission and reflection spectra of the deposited film were recorded in the wavelength range of 550–2500 nm. The refractive index, film thickness, and the optical absorption coefficient of the deposited film were successfully determined from the transmission spectrum employed the Swanepoel method. The dispersion of the refractive index was discussed in terms of Wemple–DiDomenico single oscillator model. Analysis of the optical absorption coefficient revealed a non-direct optical transition, where the optical band gap energy was calculated. Hot probe test revealed that the deposited films showed p-type conduction. The electrical properties of the deposited film have been studied during heating/cooling cycles in the temperature range 303–525 K, where the activation energy of the conduction was determined. p-AgSbS1.5Se0.5/n-CdS/ITO heterojunction solar cell fabricated in circular shape has been studied and the cell efficiency was evaluated.

Oxygen controlled E-beam evaporation deposited p-SnOx thin film for photosensitive devices

Abstract Thin SnOx films of different thicknesses at different oxygen pressures were deposited on glass substrate using reactive E-beam evaporation technique. Significant changes in the optical and structural properties of the films with change in oxygen pressure are observed. Experimentally obtained absorption coefficient and band gap of SnOx suggests its prospective use as suitable absorber material for photoconductive and photovoltaic devices. In addition to the oxygen pressure, thickness of SnOx layer has also an important role on its optical and structural properties.

Structural, magnetic, electrical and optical studies of Cr doped nanostructured ZnO thin films for spintronics application

A series of Cr-doped ZnO thin film has been prepared by E-Beam evaporation technique. These thin films were characterized for finding change or variation in the structural, morphological, optical properties due to varying doping concentration of Cr using x-ray diffraction(XRD), Scanning electron microscopy(SEM), UV–vis spectroscopy and Photoluminescence (PL) spectrometry. The crystallite size and root mean square roughness (rms) were found to be in the range of 14 to 22 nm and 7 to 28 nm respectively for various thin films. The optical absorption was measured by UV–visible in the wavelength range of 280 to 700 nm and on increasing the doping concentration blue shift was observed. Optical band gap were found to be increased with increasing doping concentration. The electrical transport property such that resistivity, sheet resistance, and conductivity were analyzed by the Hall measurement setup and resistivity were found to be 1.39 × 10−2, 8.16 × 10−3 , 1.43 × 10−2, 9.53 × 10−2Ω-cm for pure ZnO 5% ,10% and 15% Cr doped thin film respectively. Two probe I-V characterization was also done to find out the effect of doping on current conduction. The resistance values was found to be maximum for 5% Cr whereas a increment in resistance has been observed on further increasing in the doping concentration. The samples were also investigated in the superconducting quantum interference detector (SQUID) at 300 K as well as at 5 K for magnetic characterization. It has been observed that the thin film with 5% Cr doping exhibited ferromagnetic behavior whereas paramagnetic behavior was observed on further increase in Cr concentration.

Structural, electrical, optical and thermoelectric properties of e-beam evaporated Bi-rich Bi2Te3 thin films

Bi-rich Bi2Te3 thin films are prepared at 300 K using e-beam evaporation technique. A source power of 45 W for e-beam is used. Post deposition, these as-deposited Bi-rich Bi2Te3 (Bi-BT-AD) films are annealed at 100 °C (Bi-BT-100), 200 °C (Bi-BT-200) and 300 °C (Bi-BT-300) for 1 h under a pressure of 3 × 10−4 Pa. X-ray diffraction measurements reveal the presence of Bi phase together with crystalline Bi2Te3 indicating the possible presence of Bi-rich Bi2Te3 phase in the Bi-BT-AD film. The broad peaks from Bi2Te3 (015) plane indicate nanocrystalline nature of particles. With annealing, no change in diffraction pattern is observed for Bi-BT-100. However, Bi-BT-200 and Bi-BT-300 films show the emergence of x-ray reflection from unknown phases around 2θ ~ 20° and 47°. This indicates Bi related secondary phase segregation and the thermodynamic instability for the presence of Bi in Bi2Te3 lattice. From Raman studies it is discerned that Bi secondary phase coexists along with the Bi-rich Bi2Te3 nanocrystalline grains. On vacuum annealing Bi-rich Bi2Te3 phase in thin films prevails as evidenced from the p-type electrical characteristics, while excess Bi disappears and converts into an unknown minor phase. The resistivity of all the annealed films are ~ 0.9 × 10−4 Ωcm. The Seebeck coefficients also do not show any change and remain around 33 to 36 μV/K. Thermoelectric properties of Bi-BT-100 exhibit high power factors when measured at different ΔT with a maximum of ~ 17.5 × 10−4 W/K2 m for ΔT = 100 °C. Thus, unlike the near-stoichiometric thin films, Bi-rich thin films require low temperature annealing (~100 °C) to achieve optimized parameters. Bi-rich Bi2Te3 thin films also show higher power factor compared to the near-stoichiometric thin films. Thus, favourable thermoelectric properties can be achieved at 300 K for temperature sensitive device fabrication using Bi-rich Bi 2Te3 thin films.

Investigation of electrical and compositional properties of SiO2/Au/SiO2 for nonvolatile memory application

In this work, the effects of annealing temperature on the compositional, morphological and electrical properties of SiO2/Au/SiO2 trilayer structure are investigated. SiO2 and Au layers were deposited using RF magnetron sputtering and e-beam evaporation techniques, respectively. Transmission electron microscopic images reveal the formation of Au nanocrystals. Atomic force micrographs show the variation in surface roughness with annealing temperature. Rutherford backscattering spectroscopy was employed to estimate the thickness of the trilayer structure. X-ray photoelectron spectroscopy results indicate the formation of Au nanocrystal and SiO2 tunneling and blocking layers. The hysteresis curve indicates the role of Au nanocrystals in charge storage characteristics of the device structure.

Biocompatible response of hydroxyapatite coated on near-β titanium alloys by E-beam evaporation method

Abstract Biomedical implants such as dental and orthopedic implants fails due to poor mechanical and biological properties. In order to solve this problem, Electron beam (e-beam) evaporations is used as one of the methods to deposit the hydroxyapatite (HA) on Ti-13Nb-13Zr (near β titanium alloy) and the coated implant may play a significant role in increasing the mechanical and biological properties. In the present study, Ti-13Nb-13Zr was coated with hydroxyapatite (HA) by e-beam evaporation technique. The coated alloys were morphologically analyzed by FESEM and AFM, and it demonstrates that there is an increase in the growth of calcium phosphate layer. In-vitro corrosion behavior of the coated and uncoated titanium alloys were performed by electrochemical impedance spectroscopy (EIS) studies in simulated body fluid solution. The results show that the corrosion resistance of the hydroxyapatite-coated alloy higher than that of the uncoated alloys and it evident that the HA-coated alloy have better corrosion protection for the implant application. The bioactivity of the HA-coated composites were evaluated by Hanks’ solution immersed them for seven days. The ratio Ca/P was increased gradually after soaking it for seven days. The cell viability results indicates that HA coated alloys support increase in the Osseo integration and it can be used for bone implant application.

Studies of Ag/TiO2 plasmonics structures integrated in side polished optical fiber used as humidity sensor

In this report, we investigate the effects of Ag/TiO2 integrated in side polished optical fiber. Several layers of Ag thickness has been deposited on glass substrates using electron beam (e-beam) evaporation technique in order to determinate the influence of silver with combination of TiO2 on final properties of the sensor. Several thicknesses of Ag NPs were sets to 5 nm, 7 nm, 12 nm, and 16 nm. Another layer of metal oxide, specifically titanium oxide (TiO2) is introduced, covering the Ag layer to study the effect of metal oxides toward the performance of the device. The morphology of the samples was observed using a field-emission scanning electron microscope (FESEM), Raman UV–Vis spectroscopy and Raman photoluminescence (PL) spectroscopy. A CST Microwave used to observe the electric field distribution for all the samples to support the experimental findings. Based on the simulation analysis, two thicknesses of Ag layers (7 nm and 16 nm) were selected to be coated on a side polished optical fiber and tested as a humidity sensor. TiO2 layer was introduced to see the enhancement in the sensing measurements as a suitable material for trapping the photo generated electrons and avoiding charge recombination. From this observation, it can be conclusively shows that the sensitivity of the sensor is improved with integration of Ag NPs and TiO2. Based on the experimental results, the sensor of Ag/TiO2 with 7 nm of Ag layers shows the best characteristics in humidity sensing with good sensitivity and linearity of 0.9201% and 13.4 mW/% RH, respectively.

History of very thick film and bulk sample group IIIB, IVB, VB, and rare earth materials for various vacuum applications

Thick occluder film and bulk hydride materials are extremely hard to produce without flaking or cracking. This paper discusses methods of how to prepare thick films and bulk samples (i.e., rods and wires) that have reduced stress for many applications. These include accelerator research for cancer therapy, intense neutron sources, particle-beam fusion diagnostic beam focusing studies, and mass spectrometer calibration. Thick films of ∼(≥3000 to 150 000 nm thickness of various hydrides are sensitive to oxidation and are easily contaminated by improper handling. They must be specially prepared to reduce internal stresses due to temperature variations during processing, stresses due to hydriding, and substrate configuration (i.e., curved surfaces). Discussed are techniques developed at the General Electric Neutron Devices Department, in Largo, FL, in the mid-1970s to the late 1990s to produce flaking and crack free samples of thick films and bulk samples. Items studied include Er, Sc, and Ti thick film hydrides on a Cr underlay, on various substrates, Er and Sc bulk rod samples for the first basic material heat capacity and thermal diffusivity studies as a function of hydride loading, Nb and V wires in bundles of ∼30 wires, for the first tritide neutron vibration spectra studies, and Ti wires for mass spectrometer calibration studies. Film samples were prepared by standard E-beam evaporation techniques and then non-air-exposure loaded. Bulk samples were loaded with a Sievert's precise gas quantity loading system. To produce reduced intrinsic stress (strain) in samples of Er, Sc, and Ti thick films, and bulk samples of Er, Sc, Nb, V, and Ti, special processing employing slow bakeout heating and cool down rates, slow film deposition rates, slow leak in pressure hydriding rates, followed by slow cooling rates to room temperature were used. Using the process described, very successful results were obtained.

Analysis of Dispersion Characteristics of Rayleigh Waves in Nanostructured Thin Films

The present study aims to theoretically analyze the dispersion characteristics of Rayleigh waves and verify the results through experiments. Raleigh waves are generated by scanning acoustic microscope, which are used to evaluate the thickness of thin films and the material characteristics of the samples. The transfer matrix method was used in the theoretical analysis of Rayleigh wave dispersion in thin films with slow-on-fast and fast-on-slow structures. To verify the dispersion diagram derived from the analysis, the e-beam evaporation and plasma-enhanced chemical vapor deposition technique was applied to fabricate slow-on-fast and fast-on-slow thin films of varying thicknesses. Slow-on-fast structures were created by depositing nickel (Ni) films on silicon (Si) substrates; fast-on-slow structures were produced by depositing silicon nitride (Si₃N₄) on gallium arsenide (GaAs) substrates. The scanning acoustic microscope used V(z) curves to precisely measure the velocity of the Rayleigh waves. This was to evaluate their dispersion depending on the thickness of each film. A comparison of the measured velocities against the theoretical dispersion diagram resulted in an error rate of less than 6% in the slow-on-fast structure and less than 10% in the fast-on-slow structure. In conclusion, this study confirmed that the theoretically derived dispersion characteristics correspond well with those observed in actual thin films, thereby suggesting the potential use of theoretical dispersion diagrams in evaluating the thickness and material characteristics of thin films.

Synthesis and characterization of binary ZnO–SnO2 (ZTO) thin films by e-beam evaporation technique

The binary ZnO–SnO2 (ZTO) thin films with varying SnO2 concentrations (5, 10, 15, and 20 wt%) were grown on glass substrate by e-beam evaporation technique. The prepared ZTO films were annealed at 400 °C in air. These films were then characterized to investigate their structural, optical, and electrical properties as a function of SnO2 concentration. XRD analysis reveals that the crystallinity of the film decreases with the addition of SnO2 and it transforms to an amorphous structure at a composition of 40% SnO2 and 60% ZnO. Morphology of the films was examined by atomic force microscopy which points out that surface roughness of the films decreases with the increasing of SnO2 in the film. Optical properties such as optical transparency, band-gap energy, and optical constants of these films were examined by spectrophotometer and spectroscopic Ellipsometer. It was observed that the average optical transmission of mixed films improves with incorporation of SnO2. In addition, the band-gap energy of the films was determined to be in the range of 3.37–3.7 eV. Furthermore, it was found that the optical constants (n and k) decrease with the addition of SnO2. Similarly, it is observed that the electrical resistivity increases nonlinearly with the increase in SnO2 in ZnO–SnO2 thin films. However, it is noteworthy that the highest figure of merit (FOM) value, i.e., 55.87 × 10−5 Ω−1, is obtained for ZnO–SnO2 (ZTO) thin film with 40 wt% of SnO2 composition. Here, we suggest that ZnO–SnO2 (ZTO) thin film with composition of 60:40 wt% can be used as an efficient TCO film due to the improved transmission, and reduced RMS value and highest FOM value.

Microstructural, chemical states and electrical properties of Au/CuO/n-InP heterojunction with a cupric oxide interlayer

Cupric oxide (CuO) is synthesized by simple chemical bath deposition method and deposited on n-type InP substrate using e-beam evaporation technique. First, the structural and chemical compositional analysis of CuO/n-InP are analysed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD and XPS results confirmed that the formation of CuO on n-type InP substrate. Then, Au/CuO/n-InP heterojunction is fabricated with a CuO interlayer and correlated its results with the Au/n-InP Schottky junction (SJ). The barrier height (Φb) and ideality factor (n) are extracted through I-V and C-V methods and the respective values are 0.66 eV (I-V)/0.80 eV (C-V) and 1.24, and 0.78 eV (I-V)/0.94 eV (C-V) and 1.62 for the SJ and HJ diodes, respectively. By applying Cheung's and Norde functions, the Φb, ideality factor and series resistance (RS) are derived for the SJ and HJ diodes. The derived interface state density (NSS) of HJ is lower than the SJ; results demonstrated that the CuO interlayer plays an important role in the decreased NSS. The Poole-Frenkel emission is the dominant current conduction mechanism in reverse bias of both SJ and HJ diodes.

Synthesis of hard magnetic Mn3Ga micro-islands by e-beam evaporation

The permanent magnet industry heavily depends on Nd-Fe-B and Sm-Co alloys because of their high-energy product and high room temperature coercivity. Main ingredient for having such superior magnetic properties compared to other known ferromagnetic materials is rare earth elements (Nd, Sm, Dy…). However recent worldwide reserve and export limitation problem of rare earths, shifted researchers’ focus to rare earth free permanent magnets. Among many alternatives (FePt, Zr2Co11, FeNi …), Mn-based alloys are the most suitable due to abundance of the forming elements and trivial formation of the necessary hard phases. In this study, Mn3Ga micro islands have been prepared. Mn3Ga owes its hard magnetic properties to tetragonal D022 phase with magnetic anisotropy energy of 2 MJ/m3. Thin films and islands of Cr/MnGa/Cr layers have been deposited on Si/SiO2 wafers using combination of e-beam and thermal evaporation techniques. Cr has been used as buffer and cover layer to protect the sample from the substrate and prevent oxidation during annealing. Annealing under Ar/H2 forming gas has been performed at 350oC for 10 min. Nano thick islands of 25, 50 and 100 μm lateral size have been produced by photolithography technique. Room temperature coercivity of 7.5 kOe has been achieved on 100 μm micro islands of Mn3Ga. Produced micro islands could be a rare earth free alternative for magnetic memory and MEMS applications.

Study of nanostructure and ethanol vapor sensing performance of WO3 thin films deposited by e-beam evaporation method under different deposition angles: application in breath analysis devices

This paper studies the effect of deposition angle on the crystallographic structure, surface morphology, porosity and subsequently ethanol vapor sensing performance of e-beam-evaporated WO3 thin films. The WO3 thin films were deposited by e-beam evaporation technique on SiO2/Si substrates under different deposition angles (0°, 30°, and 60°) and then post-annealed at 500 °C with a flow of oxygen for 4 h. Crystallographic structure and surface morphology of the samples were checked using X-ray diffraction method and atomic force microscopy, respectively. Physical adsorption isotherm was also used to measure the porosity and effective surface area of the samples. The electrical response of the samples was studied to different concentrations of ethanol vapor (10–50 ppm) at the temperature range of 140–260 °C and relative humidity of 80%. The results reveal that the WO3 thin film deposited under 30° angle shows more sensitivity to ethanol vapor than the other samples prepared in this work due to the more crystallinity, porosity, and effective surface area. The investigations also show that the sample deposited at 30° can be a good candidate as a breath analysis device at the operating temperature of 240 °C because of its high response, low detection limit, and reliability at high relative humidity.

Probing the Interfacial Charge-Transfer Process of Uniform ALD Semiconductor–Molecule–Metal Models: A SERS Study

Among all coating methods, atomic layer deposition (ALD), which can provide a precise thickness control at the angstrom or the monolayer level, appears to be one of the most promising techniques. To investigate the interfacial charge-transfer mechanism from semiconductor–molecule–metal systems, the order of different layers is very essential because the charge-transfer process can be affected by the interfacial contact order of different materials. Also, for TiO2/MBA/Ag charge-transfer (CT) investigation, homogeneous assembling of TiO2 with precisely controllable thickness is of great importance because the energy level of semiconductor is sensitive to its size at the nanoscale. Here, unlike previous 3D composite CT models, our semiconductor–molecule–metal interfacial CT models are fabricated with the ALD and e-beam evaporation techniques, which ensures the accuracy of the CT investigation. The surface-enhanced Raman scattering (SERS) technique is adopted in the investigation of the interfacial charge-tra...

Controlled morphological modifications of ZnO thin films by ion irradiation

Nanocrystalline thin films of zinc oxide (ZnO) of thickness 100 nm are deposited using electron beam (e-beam) evaporation technique. These films are irradiated using 75 MeV Au ion beam at two different fluences namely 1 × 1011 ions cm−2 and 5 × 1011 ions cm−2. GAXRD and Raman spectroscopic studies indicate stability of nanocrystalline phases of ZnO against irradiation. Surface morphology studies using atomic force microscopy show evolution of nanosized hillocks at the surface of the irradiated films. Nano-hillock formation is also confirmed by a blue shift of the UV–visible absorption edge. The electrical conductivity of the films is found to decreases due to irradiation induced morphological modifications. Ion irradiation technique has been effectively used for controlled modification of nanocrystalline ZnO thin film surface. The preliminary studies carried out clearly indicate that the irradiated films are suitable for various applications.

Improving the hydrogen gas sensitivity of WO3 thin films by modifying the deposition angle and thickness of different promoter layers

In this research, we tried to improve the H2 gas sensitivity of WO3 thin films by changing the deposition angle and thickness of different promoter layers (Pt and Au). The WO3 thin films of 100 nm thickness were deposited by e-beam evaporation technique on SiO2/Si substrates and then post-annealed at 500 °C with a flow of oxygen for 4 h. Two various promoter layers (Pt and Au) were deposited on the WO3 thin films by e-beam evaporation method under different thicknesses (3, 6, and 9 nm) and deposition angles (0 and 30 deg.). The sensitivity of all activated and non-activated WO3 thin films was tested to 0.1% hydrogen gas at different temperatures (40–240 °C). The investigations show that the hydrogen gas sensitivity of the samples is improved by an increase in the Pt layer thickness and oblique deposition of the Au layer. The results also show that the WO3 thin films activated with Pt layer present more reliability than the sample activated with Au layer.