Pulsed Laser Deposition Technology Research Articles

High responsivity and detectivity β-Ga2O3 solar-blind photodetectors optimized by oxygen vacancy engineering

Solar-blind photodetectors (SBPDs) are core essential components for many critical applications such as precision guidance, fire warning, and space communications. Ultra-wide bandgap semiconductor β-Ga2O3 is considered to be an ideal material for the fabrication of SBPDs. However, synthetizing β-Ga2O3 with high quality factor while simultaneously in situ modulation of electronic and optoelectronic properties to enhance performance has been challenging. Here, pulsed laser deposition (PLD) technology is used to synthesize high-quality β-Ga2O3 thin films on a sapphire substrate. The oxygen vacancy engineered β-Ga2O3 films can achieve in situ precise control of their surface morphology, optical parameters, and optoelectronic properties by simply adjusting the oxygen pressure. Meanwhile, the optimal thickness of the β-Ga2O3 film for the developing high-performance SBPD is ∼221 nm, determined by fitting and analyzing the optical parameters measured by the ellipsometry. Subsequently, the influence of oxygen pressure on the performance of β-Ga2O3 SBPD is thoroughly explored, considering the optimization of electrode size and deposition time. When the oxygen pressure is set to 15 Pa, the β-Ga2O3-based SBPD achieves highly competitive responsivity (R) and detectivity (D*) at 250 nm, with values of 1080 A·W−1 and 1.4 × 1016 cm·W−1·Hz1/2, respectively. Additionally, the noise component of the β-Ga2O3 SBPD is further studied to calibrated the traditional device performance results. This work introduces a simple and straightforward approach to in situ tuning of the optoelectronic properties of β-Ga2O3, which is important for advancing β-Ga2O3 film growth technology and fabricating high-performance photodetectors.

A novel photoelectrochemical based water splitting and uric acid biosensing using PLD grown In2Se3 thin films

By altering the deposition pressure during the film growth process using the pulsed laser deposition (PLD) technology, indium selenide (In2Se3) thin films have been optimized to produce their distinct phases. The phase purity, optical and morphological studies were carried out using XRD, Raman spectroscopy, XPS, UV–visible spectroscopy, AFM and FESEM measurements. A high absorption in the visible region is observed for In2Se3 thin films with suitable band edges for hydrogen evolution. Photoelectrochemical (PEC) activity for In2Se3 photoelectrodes having various phases was analyzed based on CV and I-t response. A good charge transport characteristics were observed using the EIS measurements on PLD grown In2Se3 thin films. The Mott–Schottky analysis for the charge carrier density, flat band potential, and depletion layer width was performed for the deposition pressure dependent phase formation and high performance for PEC water splitting conversion efficiency of 0.48 %, 0.57 % and 0.98 % corresponding to α-In2Se3, β-In2Se3 and γ-In2Se3 were observed, respectively. The as prepared In2Se3 thin films were employed for the detection of Uric Acid (UA) using the cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry. The high sensitivity (0.38 mA/mM), selectivity and repeatability of the prepared biosensor demonstrates In2Se3 as potential candidate for the PEC based water splitting and biosensing application without the presence of an external mediator and can work in the self-powered mode.

Brushy C-Decorated BiTe-Based Thermoelectric Film for Efficient Photodetection and Photoimaging.

Current strategies for simultaneously achieving high thermoelectric performance and high light absorption efficiency still suffer from complex steps and high costs. Herein, two kinds of amorphous thermoelectric films of n-type Bi2Te3 and p-type Bi0.5Sb1.5Te3 with high Seebeck coefficients were prepared by pulsed laser deposition (PLD) technology. In addition, C-decorated films with excellent light absorption efficiency at the junction of the thermoelectric legs were prepared by simple drop coating and reactive ion etching (RIE) method. The TE/C-RIE composite device exhibits excellent photodetection performance under the conditions of simulated natural light, monochromatic light, and high-frequency chopping. The maximum responsivity and specific detectivity of the device can reach 153.58 mV W-1 and 6.97 × 106 cm Hz1/2 W-1 (under simulated natural light), respectively. This represents an improvement rate of 85.91% compared to that of the pure TE device. Benefiting from the excellent photodetection efficiency of the device and integration advantage of PLD technology, the composite structure can be expanded into integrated photoimaging devices. The accurate identification of patterned light sources with letters (T, J, and U) and digitals (0-9) was successfully realized by associating the response electrical signals of each electrode with the position coordinates. This work provides valuable guidance for the design and fabrication of wide-spectrum photodetectors and complex optical imaging devices.

Wafer-scale mesoporous GaN distributed bragg reflectors with enhanced luminescence for Eu doped β-Ga2O3 thin films

Wafer-scale Mesoporous GaN (MP-GaN) distributed Bragg reflectors (DBRs) with high reflectivity (>99 %) are prepared by electrochemical etching, and then are used as the substrate in growth of large-area europium (Eu) doped Ga2O3 thin films via the pulsed laser deposition (PLD) technology. X-ray diffraction analysis shows that all Ga2O3 thin films with different doping concentration have monoclinic β-Ga2O3 structures with [−201] orientation. The angle of β-Ga2O3 (−201) peak decreases as Eu contents increases, which is due to the fact that Eu3+ substituting for Ga3+ rises the lattice constant of β-Ga2O3. With the increase of Eu doping, the photoluminescence (PL) of the Ga2O3 thin film is enhanced. The epitaxial relationship is β-Ga2O3 (−201) || GaN (0001) with β-Ga2O3 [010] || GaN [-12-10]. Compared to the sample without DBRs, wafer-scale Ga2O3 thin films with MP-GaN DBRs exhibit a markedly increased PL intensity, which is attributed to improved internal quantum efficiency (IQE) of Ga2O3 thin films and enhanced light extraction efficiency (LEE) related to the light reflection effect of MP-GaN DBRs.

Energy Storage Performance of (Na0.5Bi0.5)TiO3 Relaxor Ferroelectric Film

The (Na0.5Bi0.5)TiO3 relaxor ferroelectric materials have great potential in high energy storage capacitors due to their small hysteresis, low remanent polarization and high breakdown electric field. In this work, (Na0.5Bi0.5)TiO3 thin films with ~400 nm were prepared on (001) SrTiO3 substrate by pulsed laser deposition technology. The (Na0.5Bi0.5)TiO3 films have good crystallization quality with a dense microstructure and relaxor ferroelectric properties, as confirmed by the elongated hysteresis loops and the relation of <A>∝Eα. A high Eb of up to 1400 kV/cm is obtained, which contributes to a good Wrec of 24.6 J/cm3 and η of 72% in (Na0.5Bi0.5)TiO3 film. In addition, the variations of Wrec and η are less than 4% and 10% in the temperature range of 20–120°C. In the frequency range of 103 Hz–2 × 104 Hz, the variations of Wrec and η are less than 10%. All those reveal the great potential of NBT film for energy storage.

Emergent high-temperature insulating ferromagnetism in Sr4Fe5CoO13- δ epitaxial thin films

High-temperature ferromagnetic insulators play a crucial role in a wide range of emerging magnetoelectricity phenomena and hold the potential to become fundamental components of upcoming spintronic devices. However, the strong interaction between ferromagnetism and metallic properties presents a challenge, impeding the development of high-temperature ferromagnetic insulators based on oxides. Heterostructures or superlattice materials, especially those containing perovskite layers, offer a forward-looking solution. In this work, high-quality Sr4Fe6O13 (SFO) and cobalt-doped SFO (Sr4Fe5CoO13-δ, SFCO) thin films were grown on Nb-SrTiO3(001) substrates using pulsed laser deposition technology. The grown SFO films exhibit paramagnetism, possibly due to the transition of their film structure from the orthorhombic to the tetragonal phase. In contrast to SFO films, high-quality SFCO thin films exhibit significant ferromagnetism at room temperature, with Curie transition temperature as high as 800 K. This phenomenon is mainly attributed to the formed Dzyaloshinskii–Moriya interactions between Fe–O–Co and increased lattice distortions caused by Co-doping. In contrast, the Curie transition temperature of the SFCO film is slightly higher than that of the SFCO ceramics. This enhancement is likely due to surface effects, where an increase in surface energy introduces additional energy barriers at the film surface and interface, thereby enhancing the thermal stability of the film. These characteristics advance the research of high-temperature magnetic insulators and broaden the operating temperature range of spintronic devices based on ferromagnetic insulators.

High‐Throughput Exploration of Phase Evolution in (Pb1−XBaX)ZrO3 Thin Films

AbstractAntiferroelectric thin films hold significant potential for bringing novel physics phenomena and fascinating properties. Their applications are often intertwined with the antiferroelectric‐ferroelectric phase transition, which is contingent on the chemical compositions of the constituent material. Nevertheless, the prevailing trial‐and‐error‐based research methodology is ill‐suited for the exploration of the relationship between chemical compositions and the antiferroelectric‐ferroelectric phase transition. To address this challenge, a high‐throughput synthesis strategy for antiferroelectric thin films is presented, which is enabled by an advanced high‐throughput pulsed laser deposition technology. The effectiveness of this synthesis strategy using (Pb1−XBaX)ZrO3 and achieving precise control over the parameter X is showcased. This approach allows for the deposition of (Pb1−XBaX)ZrO3 thin films encompassing nine chemical compositions ranging from X = 0 to X = 0.08. Based on this high‐throughput method, the composition that corresponds to the phase transition of (Pb1−XBaX)ZrO3, falling within the range of X = 0.04 to X = 0.06 is pinpointed. Furthermore, a temperature‐dependent correlation between the phase transition and chemical composition is established. This work not only presents a practical routine for establishing a comprehensive map of material chemical composition in relation to the properties of antiferroelectric thin films but also offers a method for the high‐throughput exploration of complex oxide thin films.

Effects of film thickness on crystal structure, surface topography, optical, and photoelectric properties of Ga2O3 thin film based solar blind photodetectors

β-Ga2O3 epitaxial thin films with different thicknesses were grown on Al2O3 (0001) substrates by the pulse laser deposition technology. The full width at half maximum of XRD rocking curve, grain size, surface roughness, and optical absorbance (200–300 nm) of the β-Ga2O3 films increase with increasing film thickness. In addition, with increasing film thickness, the adsorption edge presents a red-shift phenomenon, which is accompanied by a slight decrease in the optical band gap (). The metal-semiconductor-metal type photodetector made with the 401-nm β-Ga2O3 film shows the maximal photocurrent (1.06 μA @ 10 V), photo-to-dark current ratio (6.96 × 104), responsivity (90 mA W−1), and detectivity (0.5 × 1011 Jones) under 254-nm UV light illumination with a light intensity of 98.4 μW/cm2. Moreover, the 401-nm photodetector displays a small rise time of 0.111/0.561 s and a decay time of 0.046/0.047 s as well as a good stability and repeatability. These findings provide useful reference for the fabrication of β-Ga2O3 film based solar blind ultraviolet photodetectors.

Relaxor Ferroelectric AgNbO3 Film Fabricated on (110) SrTiO3 Substrates via Pulsed Laser Deposition

AgNbO3-based materials have attracted extensive attention in energy storage due to their double hysteresis loops, but they suffer from low breakdown strength (Eb). AgNbO3 films with few defects and small thickness exhibit high Eb, which helps to improve the energy storage performance. In this work, we successfully prepared AgNbO3 thin films on (110) SrTiO3 substrate using pulsed laser deposition technology. The AgNbO3 film shows good crystalline and relaxor ferroelectric behavior. A high Eb up to 1200 kV/cm is obtained in AgNbO3 film, which contributes to good recoverable energy storage density Wrec up to 10.9 J/cm3 and energy efficiency η of 75.3%. Furthermore, the Wrec remains above 2.9 J/cm3 and the η varies between 72.5% and 82.5% in a wide temperature range of 30–150 °C. This work reveals the great potential of relaxor ferroelectric AgNbO3 film for energy storage.

Preparation and tribological properties of NiCr–Mo–Ag–O/Mo–V–Ag–O bilayer film at RT-1000 °C

The primary objective of this research is to investigate the structure and tribological properties of NiCr–Mo–Ag–O/Mo–V–Ag–O bilayer films in a wide temperature range (RT-1000 °C). The bilayer films were prepared by pulsed laser deposition (PLD) technology, so as to provide the theoretical basis and experimental guidance for the study of the synergistic lubricating effect of Mo and V bimetallic lubricating oxides. The NiCr–Mo–Ag–O composite target was fabricated by the hot-press sintering technique. Subsequently, a NiCr–Mo–Ag–O/Mo–V–Ag–O bilayer film was deposited on Inconel 718 by pulsed laser deposition (PLD). The tribological properties of the film were evaluated by HRT-1000 high-temperature ball-on-disc configuration at RT-1000 °C. The obtained results reveal that the NiCr–Mo–Ag–O target is marked by a compact structure and homogeneous composition. Furthermore, the composite film exhibits a smooth surface and dense structure, comprised of polycrystalline and amorphous phases. The measured hardness and elastic modulus of the film approximated 4.9 GPa and 153.5 GPa, respectively. Additionally, the lowest friction coefficient of the film is about 0.28 at 800 °C. Upon reaching this temperature, the cooperative lubrication resulting from NiMoO4, Ag2Mo2O7, and AgVO3 contributed effectively towards reducing the film's friction coefficient.

Remarkable average thermoelectric performance of the highly oriented Bi(Te, Se)-based thin films and devices

Bi(Te, Se)-based compounds have attracted lots of attention for nearly two centuries as one of the most successful commercial thermoelectric (TE) materials due to their high performance at near room temperature. Compared with 3D bulks, 2D thin films are more compatible with modern semiconductor technology and have unique advantages in the construction of micro- and nano-devices. For device applications, high average TE performance over the entire operating temperature range is critical. Herein, highly c-axis-oriented N-type Bi(Te, Se) epitaxial thin films have been successfully prepared using the pulsed laser deposition technology by adjusting the deposition temperature. The film deposited at ∼260 °C demonstrate a remarkable average power factor (PFave) of ∼24.4 μW·cm−1·K−2 over the temperature range of 305–470 K, higher than most of the state-of-the-art Bi(Te, Se)-based films. Moreover, the estimated average zT value of the film is as high as ∼0.81. We then constructed thin-film TE devices by using the above oriented Bi(Te, Se) films, and the maximum output power density of the device can reach up to ∼30.1 W/m2 under the temperature difference of 40 K. Predictably, the outstanding average TE performance of the highly oriented Bi(Te, Se) thin films will have an excellent panorama of applications in semiconductor cooling and power generation.

Preparation of Novel Heterodimensional Structured Chalcogenide Semiconductor Nano‐Film by Pulsed Laser Deposition Technology

AbstractChalcogenide based nano‐films have attracted considerable attention as a new type of semiconductor material in the fields of optical waveguides, laser devices, and solar cells. However, it remains challenging to use them effectively in a variety of fields, mainly due to their intricate fabrication procedures and limited electrical characteristics. In this study, zinc selenide (ZnSe) is doped with molybdenum (Mo) and gallium (Ga). The heterodimensional structured chalcogenide semiconductor nano‐film is obtained by pulsed laser deposition (PLD). The results of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) confirm that the structure of the nano‐film is compact and the composition is uniformly distributed. The transmittance of all samples is close to 100% in the 400–2000 nm range shown. The P/N type of the film can be controlled by changing the preparation conditions. All the results indicate that the novel heterodimensional structured chalcogenide semiconductor nano‐film in this study has a simple and efficient preparation method, controllable composition, and unique optical/electrical properties. These properties can be used in integrated circuits and photovoltaic power generation.

High‐Throughput Screening Thickness‐Dependent Resistive Switching in SrTiO3 Thin Films for Robust Electronic Synapse

AbstractThe functionalities and applications of oxide thin films are highly dependent on their thickness. Most thickness‐dependent studies on oxide thin films require the preparation of independent samples, which is labor‐intensive and time‐consuming and inevitably introduces experimental errors. To address this challenge, a general strategy based on high‐throughput pulsed laser deposition technology is proposed to precisely control the thin‐film thickness in local regions under similar growth conditions. The as‐proposed synthesis strategy is demonstrated using typical complex oxide materials of SrTiO3 (STO). Consequently, high‐throughput STO thin films with nine gradient thicknesses ranging from 10.1 to 30.5 nm are fabricated. Notably, a transition from the unipolar to the bipolar resistive switching mode is observed with increasing STO thickness. Moreover, a physical mechanism based on the heterostructure‐mediated redistribution of oxygen vacancies is employed to interpret the transition between the two memristive patterns. The screening of STO thin films with different resistive switching behaviors revealed that the STO thin film with a thickness of 20.3 nm exhibit excellent conductance modulation properties under the application of electrical pulses as well as significant reliability for the emulation of various synaptic functions, rendering it a promising material for artificial neuromorphic computing applications.

Superior Electrochemical Performance of a Ce0.8Gd0.2O2-δ/Zr0.8Sc0.2O2-δ Thin Bilayer-Protected Gadolinium-Doped Ceria Electrolyte in Intermediate-Temperature Solid Oxide Fuel Cells.

To improve the performance of the Ce0.8Gd0.2O2-δ (GDC) electrolyte in a solid oxide fuel cell, it is necessary to block the electronic conduction due to Ce3+/Ce4+ transitions occurring at elevated temperatures. In this work, a GDC/ScSZ double layer consisting of 50 nm GDC and 100 nm Zr0.8Sc0.2O2-δ (ScSZ) thin films were deposited on a dense GDC substrate by the pulsed laser deposition (PLD) technology. The effectiveness of the double barrier layer in blocking the electronic conduction of the GDC electrolyte was investigated. The results showed that the ionic conductivity of GDC/ScSZ-GDC was slightly lower than that of GDC in the temperature range of 550-750 °C, but the difference gradually decreased with the increase in temperature. At 750 °C, the conductivity of GDC/ScSZ-GDC was 1.54 × 10-2 S·cm-1, which was almost the same as that of GDC. The electronic conductivity of GDC/ScSZ-GDC was 1.28 × 10-4 S·cm-1, which was lower than that of GDC. The conductivity results showed that the ScSZ barrier layer can reduce electron transfer effectively. More obviously, the open-circuit voltage and the peak power density of the (NiO-GDC)|GDC/ScSZ-GDC|(LSCF-GDC) cell were higher than those of the (NiO-GDC)|GDC|(LSCF-GDC) cell in the temperature range of 550-750 °C. The superior performance of the GDC/ScSZ-GDC electrolyte is attributed to the ScSZ thin layer, which is effective in blocking the electronic conduction of the GDC electrolyte.

Flexible oriented α-Cu2Se films and devices with remarkable power factor and output power at near-room temperature

Cu2Se has attracted great attention as a new promising thermoelectric (TE) material because of its high performance, environmentally friendly features and low cost. So far, most studies on Cu2Se focused on the β-phase bulks at medium temperature. However, in terms of commercial applications, α-phase Cu2Se with high TE performance at near-room temperature are highly desired, especially for the flexible thin films which have unique advantages in constructing wearable microelectronic devices. Herein, flexible b-axis oriented α-phase Cu2Se thin films are prepared by pulsed laser deposition (PLD) technology. The in-plane PF of the obtained flexible thin films reaches up to ∼17.6 μW cm−1K−2 at room temperature, which is much higher than that report for Cu2Se random-oriented bulks. In addition, flexible TE thin film devices are developed based on the oriented α-Cu2Se films with ∼3% fluctuation in resistance after bending for 1500 times. The maximum power density of the device is as high as ∼10.2 W m−2 under temperature difference of ∼40 K. Expectedly, the remarkable PF and output power of the thin films and devices as well as the preparation technology with precise controllable proportion will further promote the application of flexible TE materials as self-sufficient energy sources in wearable electronic devices.

Self-powered ultraviolet photodetectors based on CuInO2: Ca/GaN epitaxial heterojunction

In this paper, calcium-doped p-type CuInO2 (CuInO2:Ca) epitaxial films with c axis preferred orientation were grown on n-type GaN (001) substrates by the pulsed laser deposition (PLD) technology, and CuInO2/GaN p-n heterojunction photodetectors were fabricated based on the prepared CuInO2 films. The lattice structure, surface morphology, energy band structure, composition, and electrical properties of the grown CuInO2:Ca films were characterized. Compared with the undoped and Ca-doped (1 at.%) films, the photoresponsivity (R), detectability (D*) and rise (τr)/decay (τd) time of the detector based on the CuInO2:Ca (2 at.%)) film with the best crystal quality are 1.13 mA/W, 9.9 × 1010 Jones, and 0.14/0.1 s, under the irradiation of 365 nm (21.5 mW/cm2) UV light with 0 V bias, respectively, and can achieve a maximum R-value of 1.6 mA/W under the lowest light intensity (2.4 mW/cm2). The results indicate that the self-powered UV photodetectors based on CuInO2/GaN p-n heterojunctions have potential applications in the field of optoelectronic devices.

Mechanically tunable thickness-dependent magnetic properties of flexible SrRuO[formula omitted] thin films

A series of SrRuO3 (SRO) single crystalline thin films were grown epitaxially on the flexible substrate of fluorophlogopite by using pulsed laser deposition technology with a BaTiO3 (BTO) buffer layer. The temperature and magnetic field dependences on magnetization were measured as the external field which is parallel and perpendicular to the film surface. The results indicate that the magnetic properties of SRO thin films, including Curie temperature TC, saturation magnetization MS, and coercivity HC, are strongly dependent on the film thickness and the bending state. MS increases from 280.63 to 422.39 emu/cm3 as the film thickness increases from 50 to 200 nm while HC decreases from 1.35 to 0.72 T. TC is slightly increased from 155.41 to ∼160 K as the SRO thin films are subjected to convex or concave bending states. The regulation of mechanical bending and the variation of the film thickness exert significant influences on the magnetic properties of the SRO thin films and their potential application in flexible devices.

CuInO2 epitaxial thin films on epi-GaN wafer: Fabrication and solar-blind photodetector

High-quality p-type CuInO2 epitaxial thin films with a bandgap of ∼3.99 eV were grown on epitaxial GaN (001) (epi-GaN) wafers by using pulsed laser deposition technology. At a constant growth temperature of 750 °C, the quality of the CuInO2 thin film increases with the decrease in oxygen pressure within the range of 0.09–1 Pa. For the single crystal film obtained at 0.09 Pa, the epitaxial relationship between the film and the substrate is determined to be CuInO2 (001) || GaN (001) with CuInO2 〈100〉 || GaN [100]. The self-powered ultraviolet photodetector prepared based on the highest quality film shows high photoresponsivity 0.31 mA/W and fast response speed (rise time: 0.34 s, decay time: 0.34 s) at zero voltage under 254-nm UV-light, meaning good solar-blind photoresponsivity.

Characteristics of β-tricalcium phosphate/ZrO2 composite films deposited by pulsed laser deposition at different laser fluences

In this paper, the β-tricalcium phosphate (β-TCP)/ZrO2 composite films were prepared at different laser fluences using pulsed laser deposition technology, and the effects of different ablation fluences on the morphology, structure, mechanical properties and in vitro biocompatibility of the films were investigated. The morphology and structure were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), the nanohardness and Young's modulus of the films were measured by nanoindentation technique, and the bioactivity of the composite films was studied with simulated body fluid (SBF). The results showed that the increase of ablation fluence increased the number of irregular particles and droplets on the surface of the film, and the intensity of diffraction peaks indicated that the crystallinity level was also improved. The film deposited at 1.02 J/cm2 exhibited nanohardness and Young's modulus of 5.69 ± 0.28 GPa and 176.33 ± 2.73 GPa higher than the low-fluence film. The high-fluence film rapidly dissolved and re-precipitated in SBF, and the group band of the new phase of re-precipitation was stronger than that of films deposited at 0.57 J/cm2 and 0.79 J/cm2. The research results indicate that the β-TCP/ZrO2 composite film with high crystallinity, good mechanical properties and biocompatibility can be obtained by properly increasing the laser fluence.

The Effect of the Number of Laser Pulses on Some Physical Properties Affecting Gas Sensitivity of CdO Thin Films Prepared by PLD Method

In this research, thin films of cadmium oxide (CdO) were manufactured using pulse laser deposition (PLD) technology on glass substrates under pressure of (0.001 mbar) at room temperature by a laser power effect (800mj/cm) with a number of different laser pulses (N= (150-200-250 and 300)). The optical and synthetic properties of thin cadmium oxide films were studied, as well as their gas sensitivity. The optical properties of thin films were analyzed and studied using absorption spectra (UV-VIS) UV-Visible measurements show that CdO films of different thicknesses have a direct permissible transition with the band gap between (2.51) and (2.22) eV before annealing and after annealing the band gap decreases to become between (2.44) and (2.06). As for synthetic properties, they were analyzed and studied through X-ray diffraction patterns which showed the thin films are multicrystalline the grain size increase with the increase in the number of pulses from (100) pulse to (300) pulse gradually as for the effect of annealing, it also led to an increase in the size of the particles. While gas sensor properties were studied using static gas sensor system. The results of gas sensor showed that the increase in operating temperature improves film sensitivity. the maximum sensitivity of the pure CdO film to gas (NO2) was found to be 46.16% at 200°C and the number of pulses was (150). After annealing, the gas sensitivity decreased to was (34.25%) for (150) pulses.