Optical Properties Of SnO2 Films Research Articles

Effect of Sputtering Conditions on the Microstructure and Optical Properties of SnO2 Thin Films

The transmittance and surface smoothness of SnO2 thin films directly affect the performance and use of optical devices, while sputtering conditions determine the morphology and optical properties of SnO2 thin films. In order to study the effect of sputtering conditions on the morphology and optical properties of SnO2 films, the FJL-560 Magnetron sputtering system was used to prepare SnO2 films at different sputtering temperatures on silicon and glass substrates. The results show that the sputtering temperature has a significant impact on the crystallinity of SnO2 thin films. Silicon-based SnO2 thin films can achieve the optimal crystallization state at room temperature, while glass-based SnO2 thin films have an optimal crystallization temperature of 250 °C. The higher the sputtering temperature, the larger the grain size of the thin films; The substrate and temperature did not have a significant impact on the Raman spectrum peak position and waveform of SnO2 thin films, while the Raman spectrum peak intensity of glass substrate was significantly stronger than that of silicon substrate; The average transmittance of SnO2 thin film can reach around 80%, and as the sputtering temperature increases, the transmittance of the film decreases.

The structural, electrical, and optical properties of SnO2 films prepared by reactive magnetron sputtering: Influence of substrate temperature and O2 flow rate

The electrical and optical properties of SnO2 films prepared by sputtering are closely related to the substrate temperature and O2 flow rate, but the effect of these two parameters is not clearly clarified in previous investigations. In this study, the SnO2 films were deposited on glass substrate by reactive RF magnetron sputtering using Sn target at substrate temperature of room temperature (RT), 150 and 300 °C. At each substrate temperature, the structural, electrical and optical properties of the films were investigated as a function of O2 flow rate. By exposing typical films in damp-heat (DH) environment (85% relative humidity and 85 °C), the stability of electrical properties of the films was investigated. The results indicate that the SnO2 films with better transparent conductive properties can be obtained in an optimized O2 flow rate range at each substrate temperature. Compared with the crystalline films deposited at 150 and 300 °C, the amorphous films deposited at RT can achieve better transparent conductive properties (resistivity of 3.65 × 10−3 Ω cm and transmittance of 81.50% can be obtain simultaneously). However, the electrical properties of the films deposited at RT obviously degrade after DH exposure over one month. Besides, the analyses of photoluminescence (PL) spectra confirm that oxygen vacancy (VO) concentration plays a vital role in conductive properties of the films.

Influence of Dy doping on key linear, nonlinear and optical limiting characteristics of SnO2 films for optoelectronic and laser applications

In the present work, pure and dysprosium (Dy) doped SnO2 films have been fabricated through sol-gel spin coating technique. Strong influence of Dy doping is observed on structural, morphological, vibrational, linear and nonlinear optical properties of SnO2 films. X-ray diffraction study revealed that deposited films exhibit tetragonal crystal structure with preferentially grown along (2 0 0) plane. With increase of doping concentration in SnO2, the crystallite size decreases while dislocation density and lattice distortion ratio increases. The characteristics Raman peaks of doped SnO2 thin films broaden, shifted and intensity decreases as compared to pure film which confirm the bonding between Dy and SnO2. Optical study shows that the prepared thin films are highly transparent and absorption increases with doping concentrations owing to increase of defects states. It is also observed that the optical band gap first increases and then lessens with rise of Dy-doping concentration which attributed to the Burstein-Moss (BM) effect. Additionally, dielectric constant and refractive index first decreasing with small doping concentration (1–3%) due to increase of carrier concentration, and then increases for higher doping (5–7%) due to increase of defect in SnO2 lattice. The values χ3 and β obtained by Z-scan measurement are observed in range of 0.31 × 10−7 to 1.28 × 10−7 and 1.27 to 5.32 × 10−4 cm W−1, respectively. The limiting threshold of pure and Dy doped SnO2 nanostructured films were calculated to be in the range of 5.37–11.18 kJ/cm2.

Effect of Laser Irradiation on the Optical Properties of SnO2 films Deposited by Post Oxidation of metal Films

Tin oxide films (SnO2) of thickness (1 ?m) are prepared on glass substrate by post oxidation of metal films technique. Films were irradiated with Nd:YAG double frequency laser of wavelength (532 nm) pulses of three energies (100, 500, 1000) mJ. The optical absorption, transmission, reflectance, refractive index and optical conductivity of these films are investigated in the UV-Vis region (200-900) nm. It was found that the average transmittance of the films is around (80%) at wavelength (550 nm) and showed high transmission (? 90 %) in the visible and near infrared region. The absorption edge shifts towards higher energies, which is due to the Moss-Burstien effect and it lies at (4 eV). The optical band gap increased with increasing of energy.

Effect of Laser Irradiation on the Optical Properties of SnO2 films Deposited by Post Oxidation of metal Films

Tin oxide films (SnO2) of thickness (1 ?m) are prepared on glass substrate by post oxidation of metal films technique. Films were irradiated with Nd:YAG double frequency laser of wavelength (532 nm) pulses of three energies (100, 500, 1000) mJ. The optical absorption, transmission, reflectance, refractive index and optical conductivity of these films are investigated in the UV-Vis region (200-900) nm. It was found that the average transmittance of the films is around (80%) at wavelength (550 nm) and showed high transmission (? 90 %) in the visible and near infrared region. The absorption edge shifts towards higher energies, which is due to the Moss-Burstien effect and it lies at (4 eV). The optical band gap increased with increasing of energy.

Epitaxial relationships and optical properties of SnO2 films deposited on sapphire substrates

SnO2 thin films were grown using metalorganic chemical vapor deposition (MOCVD) system on sapphire substrates with three different orientations: r-cut (0 1 1¯ 2), a-cut (1 1 2¯ 0), and m-cut (1 0 1¯ 0). All the deposited films were epitaxial rutile films. The epitaxial orientation relationships were determined by X-ray Φ-scans: [010]SnO2||[100]Al2O3 and [1 0 1¯]SnO2||[1¯ 2¯ 1]Al2O3 for the r-cut substrate; [010]SnO2||[001]Al2O3 and [1 0 1¯]SnO2||[1 1¯ 0]Al2O3 for the a-cut substrate; [010]SnO2||[001]Al2O3 and [100]SnO2||[010]Al2O3 for the m-cut substrate. The X-ray rocking curves yielded full width at half maximum (FWHM) of 0.78°, 1.32° and 0.70° for the (101) and (002) reflections of the SnO2 films on r-, a-, and m-cut sapphire substrates, respectively. The room-temperature photoluminescence (PL) spectra of SnO2 films grown on a-cut and m-cut substrates only showed a broad deep-level luminescence band. While a UV band-edge luminescence peak was observed for the film grown on r-cut substrate.

Optical characterization of SnO2:F films by spectroscopic ellipsometry

Abstract Spectroscopic ellipsometry (SE), which is a non-destructive and a non-contact optical technique used in characterization of thin films, is widely used to determine thickness, microstructure and optical constants. In this work, the effect of F incorporation on optical properties of SnO2 films grown by ultrasonic spray pyrolysis technique (USP) is presented. The reflections, refractive indices and thicknesses of the films were investigated using room temperature spectroscopic ellipsometry. The optical constants and the thicknesses of the films were fitted according to Cauchy–Urbach model, and ellipsometric angle Ψ was used as source point for optical characterizations. Besides, transmittance spectra of the films were taken from UV spectrometer, and the optical method was used to determine the band gaps. Also, band tailing resulting from defects or impurities was investigated. From the results obtained from the optical analyses, the application potential of SnO2:F films for solar cell devices was searched.

Structural and Optical Properties of SnO<sub>2</sub> Films Grown on 6H-SiC by MOCVD

SnO2 thin films have been deposited on 6H-SiC(0001) substrates by metalorganic chemical vapor deposition (MOCVD) system. The structural and optical properties of SnO2 films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and spectrophotometry. The XRD analysis revealed that the prepared samples were SnO2 epitaxial films of rutile structure with a clear relationship of SnO2(100)// 6H-SiC(0001). The average transmittance for the deposited SnO2 samples in the visible range was about 60%.

Removal characteristics of hillock on SnO2 thin film by chemical mechanical polishing process

SnO 2 is one of the most suitable materials for gas sensors. The microstructure and surface morphology of SnO2 films must be controlled because the electrical and optical properties of SnO2 films depend on these characteristics. We investigated the effects of chemical mechanical polishing (CMP) on the variation of morphology of SnO2 films prepared by rf sputtering system. The commercially developed ceria-based oxide slurry, silica-based oxide slurry, and alumina-based tungsten slurry were used as CMP slurry. Nonuniformities of all slurries coincided with stability standards of less than 5%. Silica slurry had the highest removal rate among three different slurries. In addition, the particle size analysis showed that silica slurry had an abrasive with the largest average particle size of the three. Based on the atomic force microscopy analysis of thin film topographies and root mean square values, silica slurry has excellent properties that allow the application of SnO2 thin films as gas sensor materials.

Effect of laser irradiation on structural, electrical and optical properties of SnO2 films

Thin films of SnO2 were prepared using a spray pyrolysis technique. Films were irradiated with Nd:YAG laser pulses of various energy densities (2–50 mJ cm−2) with varying number of pulses from 1–50. X-ray diffraction studies were made to investigate the structural changes due to laser irradiation. An improvement in crystallinity and an increase in grain size were observed in laser-irradiated films. Hall coefficient and Hall mobility studies were made in the temperature range 77–300 K for the as-grown as well as laser-irradiated films. An increase in mobility and a decrease in carrier concentration were observed in the films after laser irradiation. Optical transmission studies revealed that the refractive index increased as a result of laser irradiation.

A simple and new modified CVD technique for fabrication of SnO2 films

Thin polycrystalline films of tin dioxide, SnO2, were prepared by a new modification of the chemical vapour deposition (CVD) method. Some electrical and optical properties of SnO2 films were determined as a function of the deposition conditions and doping by antimony (Sb). Attempts have been made to find the optimum deposition parameters which give SnO2 films with good optoelectronic properties, high electrical conductivity, large IR reflectance and at the same time high optical transmittance in the visible region

Determination of optical properties of SnO2 films

The optical properties of conductive transparent thin films of undoped SnO2, prepared by using magnetron supttering, were studied by measuring the transmittance and the reflectance between λ=0.25 μm and λ=3μm. The extracted optical constants are interpreted to give values of a direct band gap of the order of 4 eV and of an indirect band gap of the order of 3 eV. Typical SnO2 films transmit ≈85% of visible light, have sheet resistanceR∂ (100÷800) Ω∂ and resistivities of (2.4·10−3÷1.8·10−2) Ω cm.