Increasing Oxygen Flow Rate Research Articles

Ultrafast growth rate and high mobility In2O3 films grown on c-sapphire via low pressure chemical vapor deposition

In this study, the growth of unintentionally doped semiconductor indium oxide with ultrafast growth rates on c-plane sapphire by low pressure chemical vapor deposition (LPCVD) was demonstrated. The effect of key growth parameters, such as oxygen flow rate and distance between the substrate to the indium source, on the growth rate, crystalline quality, surface morphology, as well as carrier transport properties were studied. The growth rate is highly dependent on the oxygen flow rate and the distance between the indium source and the substrate: (i) the growth rate reaches 113 μm/h with an oxygen flow rate of 75 sccm under the investigated growth condition; and (ii) it decreases exponentially with the increase of distance between the indium source and the substrate. X-ray diffraction characterization of the as-grown films indicates that the increase of oxygen flow rate leads to the suppression of (100) facet formation, significantly influencing the film morphology. The LPCVD growth conditions also determine the background doping and carrier mobility. With an oxygen flow rate of 75 sccm, a high electron mobility of 126 cm2 V−1 s−1 with a bulk concentration of 3.9 × 1017 cm−3 was obtained. Results from this work provide guidance on LPCVD growth of In2O3 with targeted growth rate, surface morphology, carrier concentration, and mobility.

Effect of Oxygen Flow Rate on Structural, Electrical and Optical Properties of Zinc Aluminum Oxide Thin Films Deposited by DC Magnetron Sputtering

Zinc Aluminum Oxide thin films were deposited on glass substrates by reactive DC magnetron sputtering method by varying oxygen flow rates from 1 to 4 sccm. Glancing angle X-ray diffraction patterns ofzinc aluminum oxide thin films exhibits (0 0 2) peak with c-plane preferentially oriented parallel to the substrate. The surface morphology and elemental analysis of the films was observed by field emission scanning electron microscopy attached with energy dispersive X-ray analysis spectroscopy. An average optical transmittance of 83–90% is obtained for the films deposited at various oxygen flow rates. The optical band gap of the films increases from 3.41 to 3.53 eV with the increase of oxygen flow rate due to Burstein–Moss effect. The optical dispersion parameters such as dispersion energy (Ed), oscillator energy (Eo) and static refractive index (no) were determined using the Wemple-DiDomenico (W-D) single oscillator model. The nonlinear optical parameters such as optical susceptibility (χ(1)), third order nonlinear optical susceptibility (χ(3)) and nonlinear refractive index (n2) were also determined.

Investigation on electrical properties of indium tin oxide thin films by effective control of crystallographic orientation

Although indium tin oxide (ITO) film has been widely used in optoelectronic devices, it remains difficult to systemically determine the structural properties' influence on electrical properties for ITO. In this work, ITO films are grown by metal organic chemical vapor deposition (MOCVD). By introducing nucleation layers, the structural properties could be controlled effectively so that the dependence of electrical properties on crystallographic orientation and O2 partial pressure could be investigated separately. It is found that (1) for the samples grown with the same doping level, the decrease in carrier concentration with increasing oxygen flow rate is purely attributed to the increasing O2 partial pressure rather than different crystallographic orientation; (2) electron mobility of the ITO films is strongly affected by crystallographic orientation and it decreases with (100)-grain density. Analysis by using carrier's transport theory reveals that the averaged barrier height of grain boundary scattering increases with the (100)-grain density.

Effect of oxygen flow rate on structural, electrical and optical properties of zinc aluminum oxide thin films deposited by DC magnetron sputtering -=SUP=-*-=/SUP=-

AbstractZinc Aluminum Oxide thin films were deposited on glass substrates by reactive DC magnetron sputtering method by varying oxygen flow rates from 1 to 4 sccm. Glancing angle X-ray diffraction patterns ofzinc aluminum oxide thin films exhibits (0 0 2) peak with c-plane preferentially oriented parallel to the substrate. The surface morphology and elemental analysis of the films was observed by field emission scanning electron microscopy attached with energy dispersive X-ray analysis spectroscopy. An average optical transmittance of 83–90% is obtained for the films deposited at various oxygen flow rates. The optical band gap of the films increases from 3.41 to 3.53 eV with the increase of oxygen flow rate due to Burstein–Moss effect. The optical dispersion parameters such as dispersion energy ( E _ d ), oscillator energy ( E _ o ) and static refractive index ( n _ o ) were determined using the Wemple-DiDomenico (W-D) single oscillator model. The nonlinear optical parameters such as optical susceptibility (χ^(1)), third order nonlinear optical susceptibility (χ^(3)) and nonlinear refractive index ( n _2) were also determined.

Prospective Experience of High-flow Nasal Oxygen During Bronchoscopy in 182 Patients: A Feasibility Study.

High-flow nasal oxygen (HFNO) has recently gained popularity during administration of anesthesia in a variety of circumstances, including apneic oxygenation. Fully qualified anesthesiologists provide sedation for our outpatient bronchoscopy service. We adopted this therapy to assess its efficacy providing optimal conditions (using a variety of sedation regimens) for patient and bronchoscopist. We aimed to conduct a prospective feasibility evaluation. We collected data from all patients undergoing outpatient bronchoscopy or endobronchial ultrasound with anesthesiologist administered sedation over 21 months. Demographic data, high-flow settings, sedation techniques, and oxygen saturations (SpO2) were collected for each patient. Feedback from the bronchoscopists and anesthesiologists was recorded. Failure of the technique was defined as abandonment of the procedure or prolonged desaturation not amenable to basic airway maneuvers or increase in oxygen flow rate. All 182 patients underwent satisfactory bronchoscopy or endobronchial ultrasound. Mean age was 63 (±14) years. High-flow rate varied from 10 to 70 L/min. All patients received a remifentanil infusion and 175 (96%) had a propofol infusion. SpO2 before the procedure were lower (96%) than the highest saturation during the procedure with high flow (100%, P<0.0001). Ten patients transiently desaturated to <89%. Some had their flow rates increased, others required a transient jaw thrust, but all patient's saturations rapidly returned to satisfactory levels. One patient became apneic during sedation. Respiration returned after pausing the sedation and oxygen SpO2 remained above 93% throughout. All bronchoscopists and anesthesiologists were happy with the use of HFNO. HFNO has been shown to be effective in the outpatient bronchoscopy setting. Further evaluation regarding flow rates and levels of sedation is required.

Deposition of ZrON thin films by reactive magnetron sputtering using a hollow cylindrical target

ZrON films were prepared on quartz glass and glassy carbon substrates by reactive sputtering using a hollow cylindrical cathode with a Zr target. In the cathode cylinder, the plasma density increased with increasing lateral distance from the axial center of the cylinder, whereas it decreased with increasing lateral distance from the cylinder. The damage to the substrates during film deposition was evaluated by the transmission spectra of Rhodamine B films before and after sputtering. The film deposition was performed in Ar and N2 gas flows with various O2 flow rates while heating the substrates with a ceramic heater. Scanning electron microscope observation indicated homogeneous thickness of the films. X-ray diffraction measurement showed that the ZrON films were a mixture of crystalline ZrN, Zr2ON2, Zr7O8N4, and ZrO2 phases. The fractions of these crystalline phases in the films depended on the O2 flow rate. X-ray photoemission spectroscopy measurement and its analysis revealed that the binding energy of the Zr 3d doublet corresponding to precipitated ZrON crystals in the films, such as Zr2ON2 and Zr7O8N4, increased with increasing oxygen flow rate. Electrochemical measurement revealed that the film deposited at an O2 flow rate of 0.6 sccm had the largest redox potential of 0.51 V (vs standard hydrogen electrode, −5 μA/cm2). The Zr7O8N4 crystals precipitated in the film play a key role in achieving the high redox potential.

Effect of oxygen addition on microstructure and mechanical properties of quaternary TNTZ superelastic thin films obtained by magnetron sputtering

The superelastic thin films (SETF) have an enormous potential for various industrial sectors particularly in biomedical applications. The present work focuses on the influence of oxygen addition on the superelasticity and mechanical performance of Ti–23Nb–0.7Ta–2Zr (TNTZ-(O), at.%) “Gum metal” thin films deposited by DC magnetron sputtering under a mixture atmosphere of oxygen and argon. Many experimental investigations were carried out to evaluate the microstructure modifications, elasticity and hardness of films. Nanoindentation tests showed that adding oxygen led to improve Young's modulus and hardness of TNTZ films. The microstructure analysis showed that preferential orientation and superelasticity of films seem to have a strong dependence on the oxygen ratio injected during the deposition procedure. Increasing oxygen flow rate led to refine the grain size and to densify the compressive residual stress in the TNTZ-O films. The deposition of these innovative superelastic thin films under a considerable quantity of oxygen is recommended and leads to improve their mechanical properties.

Inhaled Epoprostenol Through Noninvasive Routes of Ventilator Support Systems

The administration of inhaled epoprostenol (iEPO) through noninvasive routes of ventilator support systems has never been previously evaluated. Describe the use of iEPO when administered through noninvasive routes of ventilator support systems. Critically ill patients admitted to the intensive care unit who received iEPO through noninvasive routes were analyzed. Improvements in respiratory status and hemodynamic parameters were evaluated. Safety end points assessed included hypotension, rebound hypoxemia, significant bleeding, and thrombocytopenia. A total of 36 patients received iEPO through noninvasive routes: high-flow oxygen therapy through nasal cannula, n = 29 (81%) and noninvasive positive-pressure ventilation, n = 7 (19%). Sixteen patients had improvement in their respiratory status: mean decrease in fraction of inspired oxygen (FiO2), 20% ± 13%; mean increase in partial pressure of arterial oxygen to FiO2 (PaO2/FiO2) ratio, 60 ± 50 mm Hg; and mean decrease in HFNC oxygen flow rate, 6 ± 3 liters per minute (LPM). Eight patients had declines in their respiratory status (mean increase in FiO2, 30% ± 20%; mean decrease in PaO2/FiO2 ratio, 38 ± 20 mm Hg; and mean increase in HFNC oxygen flow rate, 15 ± 10 LPM), and 12 patients had no change in their respiratory status. Conclusion and Relevance: This represents the first evaluation of the administration of iEPO through noninvasive routes of ventilator support systems and demonstrates that in critically ill patients, iEPO could be administered through a noninvasive route. Further evaluation is needed to determine the extent of benefit with this route of administration.

Tantalum oxide film deposited by vacuum cathodic arc plasma with improved electrochromic performance

Inorganic solid-state electrochromic devices (ECDs) based on tantalum oxide (Ta2O5) as ion conductor layer were fabricated by vacuum cathodic arc plasma (CAP) deposition. This work focuses on key factor of fabricating Ta2O5 film deposited by CAP through four different ratios of oxygen and argon. Our results show that refractive index mostly decreased with increasing oxygen flow rate. Refractive index of 1.9 was achieved for Ta 2O5 film with O2/Ar = 2.4 which provided high ion conduction pathways through a highly porous structure. We also observed higher ionic conductivity σi=3.5×10−6Scm−1 for Ta2O5 film at O2/Ar = 2.4 which enhanced ion's mobility for ECDs causing rapid coloring/bleaching phenomenon. As a result, excellent optical density and rapid response times were observed in fabricated device with an area of 20 cm2, exhibiting optical density of 0.63 (@550 nm) and transmittance variation T = 50% (@550 nm) with the bleaching time= 5 s and transmittance variation T = 50% (@550 nm) with the coloring time = 13 s.

Plasma assisted low temperature electron beam deposited NiO thin films for electro-optic applications

This study aims to create high quality nickel oxide (NiO) thin films at low temperatures, which is a prerequisite for coatings on temperature sensitive substrates. NiO chunks were evaporated by electron beam source, and NiO thin films were deposited at a thickness value around 250 nm. Depositions were performed at different experimental conditions: oxygen flow rate, deposition temperature, deposition rate, and plasma assistance. Deposited films were analyzed with regard to the structural, optical, and electrical aspects. X-ray diffraction (XRD) and x-ray photoelectron spectroscopy results reveal that films are grown in cubic nickel oxide phase with preferred orientation of (111) plane. Nonstoichiometry of NiO films increases with increasing oxygen flow rate and plasma assistance leads to stoichiometric NiO films. Needle, spherical, and cuboidal particle formation were seen in scanning electron microscopy (SEM) images. Grain size, lattice parameter, and grain morphology were used to explain the variations in optical and electrical properties. It was seen that the mobility of the films increases with oxygen flow rate because of enhanced grain size revealed by XRD calculations and SEM images. Plasma assistance dramatically lowers the resistivity to 150 Ω cm compared to nonassisted films possessing resistivities on the order of megaohm centimeter values. Although plasma assistance results in low mobility [0.2 cm2/(V s)], enhanced sheet carrier concentration (1.1 × 1013 cm−1) was found to be the major factor leading to high conductivity. This situation is related to denser films with higher crystallinity, which was detected from the refractive index spectrum and confirmed by SEM analysis. Optical absorption studies at 400–600 nm wavelengths revealed that absorption can be minimized by deposition under high oxygen flow rate, high deposition temperature, and low deposition rate conditions. Optical band gaps can be tuned by varying the oxygen flow rate, deposition temperature, and deposition rate. It was seen that the Fermi level and valence band minima of the films highly depend on the oxygen flow rate and can be engineered by manipulating the flow rate of oxygen and deposition conditions.

Improving Machining Efficiency Methods of Micro EDM in Cold Plasma Jet

This paper investigates the characteristics of micro electrical discharge machining (EDM) in cold plasma jet using transistor pulse generator. In order to improve the processing efficiency and quality in stable process conditions, oxygen-assisted nitrogen plasma jet, nitrogen-oxygen mixed plasma jet and external compressed air assisted nitrogen plasma jet are used in micro-EDM experiments. It was found that the material removal rate and surface roughness increases with the increase of oxygen flow rate in oxygen-assisted nitrogen plasma jet experiment. In addition, it was found that micro-EDM with a compressed air-assisted plasma jet is superior to oxygen-assisted nitrogen plasma jet in surface quality and edge quality. Nitrogen element is not found on the machined surface in micro-EDM based in NPJ or NJ. The content of oxygen element has an increasing trend when compressed air is used as an auxiliary gas.

Effect of Oxygen Flow Rate on the Optical, Electrical, and Mechanical Properties of DC Sputtering ITO Thin Films

This study presents the effect of oxygen flow rate on the optical, electrical, and mechanical properties of indium tin oxide (ITO) thin films prepared by the DC magnetron sputtering technique. The oxygen flow rate was varied from 10 to 50 sccm. The ITO thin films deposition under different oxygen flow rates exhibits different properties. We used an optical spectrometer to measure the optical transmittance and a four-point probe instrument to determine the resistivity. A home-made Twyman-Green interferometer was used to evaluate residual stress and a microscopic interferometer was used to measure the surface roughness of ITO thin films. The experimental results show that the average optical transmittance is larger than 85% in visible range; the electrical resistivity has a minimum 6.85×10-4 ohm-cm for the oxygen flow of 10 sccm. The residual stress is varied from −0.15 GPa to −0.34 GPa in the range of 10–50 sccm. The root-mean-square (rms) surface roughness is changed from 2.64 nm to 2.74 nm as the oxygen flow rate increases. The results show that the oxygen flow rate has significant influence on the electrical resistivity, residual stress, and surface roughness of the ITO thin film.

Plasma characterization in reactive sputtering processes of Ti in Ar/O2 mixtures operated in metal, transition and poisoned modes: a comparison between direct current and high-power impulse magnetron discharges

Two reactive sputtering techniques have been studied: direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS), operated in various Ar/O 2 gas mixtures using a Ti target. The processes were characterized during different modes of operation including pure argon, metallic, transition and compound mode. Energy flux data as well as data on electron density and temperature were combined to obtain knowledge about the trends and changes in the investigated internal process plasma properties for the different modes investigated. Although there is a large reduction of the mass deposition rate (a factor 10 in DCMS and a factor 14 in HiPIMS), when transiting from the metal to compound mode, we detect no significant decrease of the total energy flux in DCMS and only a minor decrease in HiPIMS ( <20%). Such a result is surprising considering that the neutral flux contribution to the total energy flux is known to be significant. Instead, we find that the reduction of the neutral component is compensated by an increase in the electron and ion flux components, which is experimentally detected as an increase of the effective electron temperature and a slightly increasing (DCMS) or essentially constant (HiPIMS) electron density with increasing oxygen flow rate.

Heavy oil upgrading at oxidation of activated carbon by supercritical water-oxygen fluid

In this paper, we have investigated for the first time heavy oil conversion under the conditions of activated carbon (AC) oxidation by supercritical water-oxygen (SCW/O2) fluid at temperature 723K, pressure 30MPa, constant flow rate of water and oil (6 and 4g/min, respectively), and variable flow rate of oxygen (0–3.5g/min). The experiment was performed by supplying the oil (from the top) and SCW/O2 fluid (from the bottom) into a vertically located tubular reactor packed with AC. The obtained time dependences of the reactor wall temperature and the power of resistance heaters allowed revealing that due to heat generation during the combustion of AC and oil high-molecular components in SCW/O2 fluid the conversion process occurs in autothermal mode. The overall yield of volatile combustibles and liquid products of oil conversion amounted to 24.0 and 59.5wt.%, respectively. It is shown that the involvement of water in redox reactions with AC and oil high-molecular components accumulated in the AC bed, contributes to the enrichment of conversion products with hydrogen (the portion of H2 and CH4 in the volatile combustible products is >60mol.%). We detected a significant decline in the fractions of asphaltene and resin, as well as the content of vanadium (V) and nickel (Ni) in the liquid products compared to crude oil due to their accumulation in the AC bed. It follows from the results of IR and 1H NMR spectroscopy that a significant increase in the content of aromatic compounds in the liquid products occurs only at the increase in oxygen flow rate up to 3.5g/min.

Measurement and modeling of plasma parameters in reactive high-power impulse magnetron sputtering of Ti in Ar/O2 mixtures

A reactive high-power impulse magnetron sputtering (HiPIMS) process using a titanium target in a mixture of Ar/O2 has been investigated for different modes of operation including pure argon, metallic, transition, and compound mode. The trends and changes in the plasma density ne and the effective electron temperature Teff, have been measured by the time-resolved Langmuir probe technique. The same experimental process conditions have also been studied using a recently developed reactive ionization region model (R-IRM), making it possible to compare the acquired experimental results with the model results. It was found that trends in the plasma density and mean electron energy as measured by the Langmuir probe are in good agreement with the results obtained from the R-IRM model for different pulse discharge current densities. The effective electron temperature generally increases with an increasing oxygen flow rate. It is likely due to a reduction of sputtered Ti, due to compound formation on the target, which forces the discharge to increase the electron energy to increase the ionization rate of the process gas (Ar/O2) to maintain a high HiPIMS discharge current. Small variations in the plasma density were detected between the middle part of the plasma pulse as compared to the end of the plasma pulse, when transitioning from the metal mode to the poisoned mode. It is found that the time-evolution of the electron density is rather well correlated with the discharge current waveform. On the other hand, the mean electron energy did not change significantly between the middle and the end of the plasma pulse. For the lower pulse discharge current, both the model and experimental data have shown a slight increase in the plasma density with increasing O2 mass flow rate.

Catalyst-free growth and tailoring morphology of zinc oxide nanostructures by plasma-enhanced deposition at low temperature

ZnO nanostructures were grown under different deposition conditions from Zn films pre-deposited onto Si substrates in O2-Ar plasma, ignited in an advanced custom-designed plasma-enhanced horizontal tube furnace deposition system. The morphology and structure of the synthesized ZnO nanostructures were systematically and extensively investigated by scanning and transmission electron microscopy, Raman spectroscopy, and atomic force microscopy. It is shown that the morphology of ZnO nanostructures changes from the hybrid ZnO/nanoparticle and nanorod system to the mixture of ZnO nanosheets and nanorods when the growth temperature increases, and the density of ZnO nanorods increases with the increase of oxygen flow rate. The formation of ZnO nanostructures was explained in terms of motion of Zn atoms on the Zn nanoparticle surfaces, and to the local melting of Zn nanoparticles or nanosheets. Moreover, the photoluminescence properties of ZnO nanostructures were studied, and it was revealed that the photoluminescence spectrum features two strong ultraviolet bands at about 378 and 399Â nm and a series of weak blue bands within a range of 440--484Â nm, related to the emissions of free excitons, near-band edge, and defects of ZnO nanostructures. The obtained results enrich our knowledge on the synthesis of ZnO-based nanostructures and contribute to the development of ZnO-based optoelectronic devices.

Effect of oxygen flow rate on the electrical and optical characteristics of dopantless tin oxide films fabricated by low pressure chemical vapor deposition

The effect of oxygen flow rate on the electrical and optical characteristics of dopantless tin oxide films prepared by low pressure chemical vapor deposition (LPCVD) was investigated. A decrease in the sheet resistance of the film with increasing oxygen flow rate in the range of 200-300 sccm was attributed to an increase in the film thickness (and correspondingly, in the grain size); while at oxygen flow rates higher than 300 sccm, the increase in the sheet resistance of the film resulted from an increase in the X-ray diffraction peak intensities of the (110), (101), and (201) planes. The optical bandgap of the film decreased when the oxygen flow rate was increased from 200 to 300 sccm, but it remained nearly constant for oxygen flow rates higher than 300 sccm. A maximum figure-of-merit was achieved for films prepared with an oxygen flow rate of 300 sccm.

Effects of dilution gas on characteristics of SiOC(H) films synthesized by atmospheric pressure plasma CVD

In this study, we synthesized SiOC(H) films by atmospheric pressure plasma enhanced CVD from trimethylsilane and oxygen gas diluted by helium, argon and nitrogen. We changed the oxygen flow rate and investigated the effect of dilution gas on the hardness of the films. The deposition rate for both helium and argon dilution increased with increasing the oxygen flow rate up to 100 ml/min. The hardness of the films diluted by argon gradually increased from 0.2 GPa to 1.1 GPa with an increase of oxygen flow rate while that of the films diluted by helium was hardly changed about 0.6 GPa. The films diluted by nitrogen exhibited high hardness at 2.3 GPa, which was highest value among the samples. The FT-IR spectra of the films showed the peaks corresponding to terminal methyl and hydroxyl bonds along with the stretching vibrations of SiOSi network bonding were observed and their intensities varied with the hardness of the films. As the oxygen flow rate increased, intensity of methyl bond decreased and that of hydroxyl bond was not increased different from the result of the films diluted by argon or helium gas. The methyl bonds are likely to prevent oxygen atom from forming SiOSi structures. The existence of terminated bonds such as methyl bond and hydroxyl bond lead to low hardness of the films. From the result of optical emission spectroscopy, peaks of nitrogen-oxygen radicals were observed at plasma diluted by nitrogen, while a large amount of oxygen radical were generated in the plasma diluted with noble gas.

Effect of oxygen on fracture toughness of Zr(N,O) hard coatings

Abstract The objectives of this study were to measure the fracture toughness (G c ) of Zr(N,O) hard coatings using internal energy induced cracking (IEIC) method, and to investigate the effect of oxygen on the fracture toughness of the Zr(N,O) coatings. Zr(N,O) coatings were deposited by unbalanced magnetron sputtering with different oxygen flow rates while maintaining constant nitrogen and argon flow rates. The elastic constants of the Zr(N,O) coatings were determined by nanoindentation, residual stress was measured by laser curvature method and the coating thickness was measured from cross-sectional images by scanning electron microscopy (SEM). Using the data of elastic constants, residual stress and coating thickness, G c could be obtained. The results showed that G c was texture dependent; for ZrN coatings with (111) texture G c was 26.7 ± 2.1 J/m 2 while that for coatings with (200) texture was 9.0 ± 0.9 J/m 2 . The fracture toughness of Zr(N,O) coatings containing small amount of zirconium oxynitride remained nearly the same as that of ZrN with (200) texture ranging from 8.7 ± 0.9 to 8.9 ± 0.6 J/m 2 . Both oxygen flow and oxygen contents were found to affect the structure and the accompanying properties of the Zr(N,O) coatings. Oxygen flow may interfere the migration of Zr adatoms and the subsequent film formation; consequently, the texture of Zr(N,O) coatings switched from (111) to (200). The oxygen contents of the Zr(N,O) coatings increased, but not substantially, with increasing oxygen flow rate. Since lower energy processing parameters were used in this study, the formation of oxide or oxynitride phases was not as distinct as that in our previous studies. The fractography showed that the main crack propagated stepwise. The crack initiation may occur due to the edge stress acting at local defects ahead of the edge inside the film. The stress distribution due to free edge effect could move with the crack front and consequently drove the main crack propagating stepwise.

Optical properties of zirconium oxide thin films for semitransparent solar cell applications

We prepared zirconium oxide thin films using reactive sputter deposition, and investigated their optical properties as a dielectric layer constituting semitransparent silicon thin film solar cells. The transmittance and reflectance of zirconium oxide thin films, deposited at various oxygen flow rates, are distinctly divided into three different ranges depending on the oxygen flow rate. Highly transparent zirconium oxide films are grown at relatively high flow rates, but they become nearly opaque at very low flow rates. Microstructural observation and refractive index measurement support that the transition from metallic zirconium-rich to dielectric zirconium oxide film proceeds as the oxygen flow rate increases. X-ray diffraction analysis indicates that the highly transparent films have a monoclinic phase of stoichiometric ZrO2. While the transmittance of the monoclinic ZrO2 films gradually decreases with an increase of film thickness, the reflectance exhibits a strong dependence on the film’s antireflection characteristic. The simulation results are in close agreement with the measured transmittance and reflectance. The simulated back reflectance of semitransparent silicon thin film solar cells demonstrates that the color of the semitransparent cells can be adjusted with the addition of the ZrO2 thin film.