Properties of nanostructured Al doped ZnO thin films grown by spray pyrolysis technique

Aluminium doped zinc oxide thin films were deposited on glass substrate by using spray pyrolysis technique. The X-ray diffraction study of the films revealed that the both the undoped and Al doped ZnO thin films exhibits hexagonal wurtzite structure. The preferred orientation is (002) for undoped and up to 3 at % Al doping, further increase in the doping concentration to 5 at % changes the preferred orientation to (101) direction. The surface morphology of the films studied by scanning electron microscope, reveal marked changes on doping. Optical study indicates that both undoped and Al doped films are transparent in the visible region. The band gap of the films increased from 3.24 to 3.36 eV with increasing Al dopant concentration from 0 to 5 at % respectively. The Al doped films showed an increase in the conductivity by three orders of magnitude with increase in doping concentration. The maximum value of conductivity 106.3 S/cm is achieved for 3 at % Al doped films.     

Properties of antimony doped ZnO thin films deposited by spray pyrolysis technique

Antimony (Sb) doped zinc oxide (ZnO) thin films were deposited on the glass substrate at 450°C using spray pyrolysis technique. Effect of Sb doping on surface morphology structural, optical and electrical properties were studied. X-ray diffraction (XRD) analysis showed that both the undoped and doped ZnO thin films are polycrystalline in nature with (101) preferred orientation. SEM analysis showed a change in surface morphology of Sb doped ZnO thin films. Doping results in a marked increase in conductivity without affecting the transmittance of the films. ZnO films prepared with 3 at % Sb shows the lowest resistivity of 0.185 Ohm cm with a Hall mobility of 54.05 cm² V^–1 s^–1, and a hole concentration of 6.25 × 10¹⁷ cm^–3.     

Elaboration and characterization of Co-doped ZnO thin films deposited by spray pyrolysis technique

The structure and the nature of magnetism of ZnO and Zn_1−xCo_xO (CZO) thin films (0?x?0.09) deposited on glass substrate at 450 °C by spray pyrolysis technique is investigated. All the CZO thin films have the ZnO wurtzite structure with a preferential orientation along the c-axis and had no impurity phase. This was also confirmed by transmission electron microscopy analysis. Transmission UV-visible spectroscopy showed that Co²⁺ was well substituted for the Zn²⁺ ions in the ZnO matrix. Magnetization measurements at low temperature show that CZO thin films present a paramagnetic behaviour and no sign of ferromagnetism.     

Growth and molarity effects on properties of alumina thin films obtained by spray pyrolysis

Various and versatile applications of alumina in materials science and engineering specially in semiconductor and energy conversion technology encouraged us to prepare and investigate its physical properties as much as possible. Hence, after depositing of alumina thin films on glass substrates by a spray pyrolysis technique, structural, morphological, and optical properties of the films were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and UV–visible spectrophotometry. Different optical quantities, such as optical band gap, refractive index and extinction coefficient, were determined in this article for different molarities (from 0.10 M to 0.25 M) at two specific substrate temperatures (250 °C and 500 °C). XRD results showed the prevailing amorphous phase in all samples as expected, whereas SEM, XPS, and FTIR presented the presence of molarity effects on alumina properties. Decrease of optical transmittance with molarity increase was notable. Using the transmittance data other optical quantities were obtained by a numerical approximation method.     

Structural, optical and electrical properties of SnxSy thin films grown by spray ultrasonic

Tin sulfide(Sn_xS_y) thin films were prepared by a spray ultrasonic technique on glass substrate at 300℃. The influence of deposition time t=2, 4, 6, 8 and 10 min on different properties of thin films, such as(XRD), photoluminescence(PL) and(UV) spectroscopy visible spectrum and four-point were investigated. X-ray diffraction showed that thin films crystallized in SnS₂, SnS, and Sn₂S₃ phases, but the most prominent one is SnS₂. The results of the(UV) spectroscopy visible spectrum show that the film which was deposited at 4 min has a large transmittance of 60% in the visible region. The photoluminescence spectra exhibited the luminescent peaks in the visible region, which shows its potential application in photovoltaic devices. The electrical resistivity(ρ) values of Sn_xS_y films have changed from 8.1×10^-4 to 1.62Ω·cm with deposition time.     

Effect of substrate temperature on the properties of ZnO thin films prepared by spray pyrolysis

Sprayed ZnO films were grown on glass at different substrate temperatures from 200 °C to 500 °C and their structural, optical and electrical properties were investigated. All films are polycrystalline with hexagonal wurtzite structure. ZnO films at substrate temperatures above 400 °C appear to be better crystalized with (002) plane as preferential orientation. Optical transmission spectrum shows that ZnO films have high transmission (above 80%) in visible region for substrate temperatures above 400 °C. Photoluminescence spectra at room temperature show an ultraviolet emission and two visible emissions at 2.82 eV and 2.37 eV. The resistivity of ZnO films increases with increasing substrate temperatures (above 400 °C). The ZnO film deposited at 400 °C shows highest figure of merit.     

Magnetic properties of ZnO:Cu thin films prepared by RF magnetron sputtering

ZnO films and ZnO:Cu diluted magnetic semiconductor films were prepared by radio frequency magnetron sputtering on Si (111) substrates, with targets of ZnO and Zn0.99Cu0.01 O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.     

射频磁控溅射法制备ZnO:Cu薄膜的磁性研究

ZnO films and ZnO：Cu diluted magnetic semiconductor films were prepared by radio frequency mag-netron sputtering on Si （111） substrates, with targets of ZnO and Zn0.99Cu0.01O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1＋. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.     

溶胶凝胶法制备钼掺杂氧化锌薄膜及性质研究

利用溶胶凝胶法在Al₂O ₃衬底上制备出了c轴择优取向的钼掺杂氧化锌（MZO）透明导电薄膜,研究了钼的掺杂量(0~1 at%)对钼掺杂氧化锌薄膜光电性能的影响。研究结果表明：所制备的薄膜为六方纤锌矿型结构且表面平整、致密,通过高温真空退火,MZO薄膜的电阻率明显降低,且随着钼含量的增加,MZO薄膜的电阻率呈现出先减小后增大的趋势,当钼含量为0.4at.%时,获得最小电阻率为0.13 Ωcm。薄膜在近红外区域(800~2000 nm)的平均透过率大于85%,这可以有效地拓宽光电器件的光谱范围。     

超声喷雾热解法制备ZnO：Eu薄膜

以醋酸锌（Zn（CH3COO）2）、氯化铕（EuCl3）水溶液为前驱体,采用超声喷雾热解（USP）方法在ITO导电玻璃衬底上沉积Eu掺杂ZnO（ZnO：Eu）薄膜。通过扫描电镜（SEM）、X射线衍射（XRD）和光致发光（PL）谱对ZnO：Eu薄膜的形貌、结构和光学性质进行了研究。SEM测试结果表明,超声喷雾热解法制备的...     

Cu2ZnSnS4 films grown in one-step process by spray pyrolysis with improved properties

This work reports results of a study carried out to improve the optical, electrical and microstructural properties of Cu₂ZnSnS₄ (CZTS) films grown by spray pyrolysis in a one-step process using a precursor solution prepared dissolving thiourea and salts of Cu, Sn and Zn in a solvent constituted by a mixture of dimethyl sulfoxide (DMSO) and acetone. The improvement of the properties of the CZTS films was achieved through a parameters study performed by using an experimental design 2³ face centered central composite design (FCCCD). The study revealed that substrate temperature (T_s), carrier gas pressure (P_g), spray pulse time (t_sp) as well as their interaction are the parameters that most critically affect the above mentioned properties. Special emphasis was done on studying the influence of these parameters on the micro structural properties of the CZTS films using the XRD peak broadening method and Williamson-Hall equations, assuming the models UDM (uniform deformation model), USDM (uniform stress deformation model) and UDEDM (uniform deformation energy density model). Further, information regarding the influence of preparation conditions on the formation of structural defects was achieved through Urbach energy measurements.     

冰乙酸在超声喷雾热分解法制备ZnO薄膜中的作用

采用超声喷雾热分解技术(USP),以二水醋酸锌(Zn(CH<,3>COO)<,2>·2H<,z>O)为原材料.在无碱玻璃衬底上制备了ZnO薄膜.对前驱液pH值、ZnO薄膜结构特性、表面形貌、电学和光学特性的研究结果表明,冰乙酸对ZnO薄膜生长速率具有重要影响.X射线衍射(XRD)和扫描电子显微镜(SEM)测试显示,所有...     

Enhancement of photoluminescence in Sr doped ZnO thin films prepared by spray pyrolysis

Photoluminescence characteristics of strontium doped zinc oxide (ZnO:Sr) thin films grown by spray pyrolysis method were investigated. The ZnO:Sr films were highly transparent having polycrystalline hexagonal wurtzite structure. A redshift of 130 meV in the optical band gap was observed owing to atomic size mismatch induced defect states and increase in the crystallite size in ZnO:Sr films. The enhancement of intensity of violet emission in room temperature photoluminescence by 250% is in correlation with the improved surface morphology at higher concentration of Sr in ZnO:Sr thin film. The observed increment in visible emissions is attributed to Sr induced oxygen vacancy related recombination in ZnO.     

Effect of Fe-doping on the structural and optical properties of ZnO thin films prepared by spray pyrolysis

Fe-doped ZnO thin films have been prepared by spray pyrolysis on glass substrates and the influence of Fe-doping concentration on the structural and optical properties of the films has been studied.The X-ray diffraction (XRD) analysis shows that Fe doping has a significant effect on crystalline quality,grain size and strain in the thin films.The best crystalline structure is obtained for 3 at%Fe doping as observed from scanning electron microscopy (SEM) and XRD.However,lower or higher Fe-doping degrades the crystalline quality in turn.Moreover,UV spectroscopy demonstrates the influence of Fe-incorporation on visible range transmittance of ZnO where the best transmittance is obtained for 3 at%doping.The results have been illustrated simultaneously focusing previous results obtained from literature.     

Indium doped zinc oxide thin films deposited by ultrasonic spray pyrolysis technique: Effect of the substrate temperature on the physical properties

Indium doped zinc oxide (ZnO:In) thin solid films were deposited on soda-lime glass substrates by the ultrasonic spray pyrolysis technique. The effect of the substrate temperature on the electrical, morphology, and optical characteristics of ZnO:In thin films was studied. It was found that, as the substrate temperature increases, the electrical resistivity decreases, reaching a minimum value in the order of 7.3×10⁻³ Ω cm, at 415 °C. Further increase in the substrate temperature results on an increment on the electrical resistivity of the thin solid films. All the samples were polycrystalline with a well-defined wurtzite structure. The preferred growth shows a switching from a random orientation at low substrates temperatures to (0 0 2) in the case of films deposited at the highest substrate temperature used. As the substrate temperature increases, the corresponding surface morphology changes from an almost faceted pyramidal to round-shaped form. The optical transmittance of the films in a interval of 400 to 700 nm is around 70%, with a band gap value in the order of 3.45 eV.     

Influence of Sn content on properties of ZnO:SnO2 thin films deposited by ultrasonic spray pyrolysis

The present work is devoted to the preparation of zinc oxide (ZnO): tin oxide (SnO₂) thin films by ultrasonic spray technique. A set of films are deposited using a solution formed with zinc acetate and tin chloride salts mixture with varied weight ratio R=[Sn/(Zn+Sn)]. The ratio R is varied from 0 to 100% in order to investigate the influence of Sn concentration on the physical properties of ZnO:SnO₂ films. The X rays diffraction (XRD) analysis indicated that films are composed of ZnO and SnO₂ distinct phases without any alloys or spinnel phase formations. The average grain size of crystallites varies with the ratio R from 17 to 20 nm for SnO₂ and from 24 to 40 nm for ZnO. The obtained films are highly transparent with a transmission coefficient equal to 80%. An increase in Sn concentration increases both the effective band gap energy from 3.2 to 4.01 eV and the photoluminescence intensity peak assigned defects to SnO₂. The films electrical characterization indicated that films are resistive. Their resistivities vary between 1.2×10² and 3.3×10⁴ (Ω cm). The higher resistivity is measured in film deposited with a ratio R equal to 50%.     

Effect of substrate temperature on structural,morphological, optical and electrical properties of MnIn2S4 thin films prepared by nebulizer spray pyrolysis technique

Manganese indium sulphide (MnIn₂S₄) thin films were deposited using an aqueous solution of MnCl₂, InCl₃ and (NH₂)₂CS in the molar ratio 1:2:4 by simple chemical spray pyrolysis technique. The thin film substrates were annealed in the temperature range between 250 and 350 °C to study their various physical properties. The structural properties as studied by X-ray diffraction showed that MnIn₂S₄ thin films have cubic spinel structure. The formation of cube and needle shaped grains was clearly observed from FE-SEM analysis. The energy dispersive spectrum (EDS) predicts the presence of Mn, In and S in the synthesized thin film. From the optical studies, it is analyzed that the maximum absorption co-efficient is in the order between 10⁴ and 10⁵ cm⁻¹ and the maximum transmittance (75%) was noted in the visible and infrared regions. It is noted that, the band gap energy decreases (from 3.20 to 2.77 eV) with an increase of substrate temperature (from 250 to 350 °C). The observations from photoluminescence studies confirm the emission of blue, green, yellow and red bands which corresponds to the wavelength range 370–680 nm. Moreover, from the electrical studies, it is observed that, as the substrate temperature increases the conductivity also increases in the range 0.29–0.41×10⁻⁴ Ω⁻¹ m⁻¹. This confirms the highly semiconducting nature of the film. The thickness of the films was also measured and the values ranged between 537 nm (250 °C) to 483 nm (350 °C). This indicates that, as the substrate temperature increases, the thickness of the film decreases. From the present study, it is reported that the MnIn₂S₄ thin films are polycrystalline in nature and can be used as a suitable ternary semiconductor material for photovoltaic applications.     

Effects of substrate temperature on the properties of CdSnSe thin films deposited by nebulizer spray pyrolysis technique

Thin films of cadmium tin selenide (CdSnSe) have been prepared on glass substrates at different temperatures by the nebulizer spray pyrolysis (NSP) technique using aqueous solutions of cadmium chloride (CdCl₂), tin chloride (SnCl₂) and sodium selenosulphate (Na₂SeSO₃). The deposited films were characterized by structural, morphological, compositional, optical and electrical properties. X-ray diffraction studies confirm that the CdSnSe films are polycrystalline in nature having mixed phase (hexagonal+cubic) crystal structure with preferential orientation (102) plane which corresponds to hexagonal crystal structure. Scanning electron microscopy studies reveal that the prepared films are having smooth and uniform surface with dense surface morphology well-covered over the entire substrate surface without any cracks. The UV–vis spectroscopy confirms the formation of good transparent CdSnSe films with an average transmission ∼60% in the visible region. Optical band gap energies of the films are found to be varied from 1.6–1.625 eV depending on the substrate temperatures. The temperature dependence of the electrical conductivity during the heat treatment was also studied. The electrical conductivity of the films is found to be in the order of 10⁻³ Ω-cm⁻¹ and increases with temperature.     

Investigation the structural, optical and electrical properties of Zinc oxide (ZnO) thin films deposited by spray pyrolysis techniqueYacine Aoun 1, Boubaker Benhaoua 2,Said Benramache 3,*

Zinc oxide (ZnO) thin films were deposited on glass substrates by spray pyrolysis technique decomposition of zinc acetate dihydrate in an ethanol solution with 30 mL of deposition rate, the ZnO thin films were deposited at two different temperatures: 300 and 350 ℃. The substrates were heated using the solar cells method. The substrate was R217102 glass, whose size was 30 × 17.5 × 1 mm³. The films exhibit a hexagonal wurtzite structure with a strong (002) preferred orientation. The higher value of crystallite size is attained for sprayed films at 350 ℃, which is probably due to an improvement of the crystallinity of the films at this point. The average trans mittance of obtain films is about 90%-95%, as measured by a UV-vis analyzer. The band gap energy varies from 3.265 to 3.294 eV for the deposited ZnO thin film at 300 and 350 ℃, respectively. The electrical resistivity measured of our films are in the order 0.36 Ω·cm.     

梯度掺杂生长绒面结构ZnO:B-TCO薄膜及其特性研究

采用新的金属有机化学气相淀积(MOCVD)-ZnO镀膜工艺技术-梯度掺杂技术生长绒面结构。研究ZnO:B-TCO薄膜。结果表明,梯度掺杂技术可有效增加薄膜晶粒尺寸和提高光散射作用。并且,梯度掺杂技术有效地提高了薄膜在近红外区域的光学透过率,有利于应用于宽谱域薄膜太阳电池。生长获得的MOCVD-ZnO薄膜,其薄膜电子迁移率为24 cm2/V,电阻率为2.17×10-3Ω.cm,载流子浓度为1.20×1020cm-3,且在小于1 000 nm波长范围内的平均透过率大于85%。