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.     

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.     

Study of some physical properties of ultrasonically spray deposited silver doped lead sulphide thin films

In this study, undoped and Ag doped PbS thin films at different concentrations were deposited onto glass substrates at 225 °C by using ultrasonic spray pyrolysis technique, in order to investigate the effect of Ag doping on the physical properties of PbS thin films. Structural investigations revealed that all doped PbS:Ag thin films have cubic structure and Ag doping enhances crystalline level of PbS thin films. It was determined that average crystallite size of PbS:Ag thin films increased from 24 nm to 49 nm by increasing Ag doping concentration. Morphological studies showed that surfaces of the films become denser after Ag doping. Optical transmittance and absorption spectra revealed that all deposited thin films have low transmission and high absorbance within the visible region and band gap energy of the PbS:Ag thin films were determined to be in the range of 1.37 eV and 1.28 eV by means of optical method. Electrical conductivity type of PbS:Ag films was determined to be p-type and calculated electrical resistivity was found to be lowest for Ag-doped PbS thin films at 2%.     

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.     

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%.     

Structural, optical and electrical properties of zinc oxide thin films deposited by a spray pyrolysis technique

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.     

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...     

Influence of pH of spray solution on optoelectronic properties of cadmium oxide thin films

Highly conducting transparent cadmium oxide thin films were prepared by the conventional spray pyrolysis technique. The pH of the spray solution is varied by adding ammonia/hydrochloric acid. The effect of pH on the morphology, crystallinity and optoelectronic properties of these films is studied. The structural analysis showed all the films in the cubic phase. For the films with pH < 7(acidic condition), the preferred orientation is along the(111) direction and for those with pH >7(alkaline condition), the preferred orientation is along the(200) direction.A lowest resistivity of 9.9104 cm(with carrier concentration D5.11020cm3, mobility D12.4 cm2/(V s))is observed for pH12. The resistivity is tuned almost by three orders of magnitude by controlling the bath pH with optical transmittance more than 70%. Thus, the electrical conductivity of CdO films could be easily tuned by simply varying the pH of the spray solution without compromising the optical transparency.     

Effect of deposition conditions on the physical properties of Sn_xS_y thin films prepared by the spray pyrolysis technique

Tin sulfide thin films（Sn_xS_y） with an atomic ratio of y/x = 0.5 have been deposited on a glass substrate by spray pyrolysis.The effects of deposition parameters,such as spray solution rate（R）,substrate temperature （T_s） and film thickness（t）,on the structural,optical,thermo-electrical and photoconductivity related properties of the films have been studied.The precursor solution was prepared by dissolving tin chloride（SnCl₄,5H₂O） and thiourea in propanol,and Sn_xS_y thin film was prepared with a mole ratio of y/x = 0.5.The prepared films were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and UV-vis spectroscopy. It is indicated that the XRD patterns of Sn_xS_y films have amorphous and polycrystalline structures and the size of the grains has been changed from 7 to 16 nm.The optical gap of Sn_xS_y thin films is determined to be about 2.41 to 3.08 eV by a plot of the variation of（αhv）² versus hv related to the change of deposition conditions.The thermoelectric and photo-conductivity measurement results for the films show that these properties are depend considerably on the deposition parameters.     

Thickness dependent physical properties of chemically deposited nanocrystalline MgSe thin films deposited at room temperature by solution growth method

Chemical bath deposition method has been employed to deposit nanocrystalline magnesium selenide thin films of thickness 104–292 nm onto glass substrates at room temperature. The deposition bath consists of magnesium chloride, triethanolamine (TEA) and selenium dioxide. The as deposited films were characterized by X-ray diffraction, scanning electron microscopy (SEM), atomic force microscopy (AFM), optical absorption, electrical resistivity and thermo-emf measurements. The X-ray diffraction (XRD) studies revealed that the crystallinity of the magnesium selenide thin film increases with thickness. SEM studies reveal that MgSe films exhibit uniform distribution of round shaped grains over the entire substrate surface.The optical band-gap and electrical resistivity of MgSe film decrease as the film thickness increases. Such type of dependence is attributed to the quantum size effect that is observed in nanocrystalline semiconductors.The thermo-emf measurement confirms its p-type conductivity.     

Effect of co-doping concentration on structural,morphological, optical and electrical properties of aluminium and indium co-doped ZnO thin films deposited by ultrasonic spray pyrolysis

In this work, we reported a chemical approach to prepare aluminium and indium co-doped ZnO thin films (AIZO) by ultrasonic spray pyrolysis. Film depositions were carried out on soda lime glass substrates at 425 °C by using a spray solution containing zinc acetate as zinc precursor, aluminium acetylacetonate as Al dopant source and indium (III) acetate as In dopant source. Physical properties such as structural, morphological, optical and electrical properties were studied with respect to the equal variations in co-dopants concentration (0.5–3 at%). X-ray diffraction patterns proved that films are poly crystalline with (002) preferential orientation. Scanning electron microscopy analysis showed that AIZO films grown like hexagonal nanopyramids, elongated grains and irregular trigonals. Optical transmittance ~85% and a minimum resistivity of 1.3×10⁻³ Ω cm, are achieved for films when co-doped with 1.5 at% of Al and 1.5 at% of In, confirm that AIZO films are suitable for transparent conductive oxide (TCO) applications.     

Influence of Mn doping on structural,optical and electrical properties of CdO thin films prepared by cost effective spray pyrolysis method

Transparent and conducting cadmium oxide (CdO) and manganese doped CdO (Mn: CdO) thin films were deposited using a low cost spray pyrolysis method on the glass substrate at 300 °C. For Mn doping, various concentrations of manganese acetate (1–3 wt%) was used in the spraying precursor solution. The structural, electrical and optical properties of CdO and Mn: CdO films were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), UV–vis and Hall measurement. X-ray diffraction study reveals that the CdO and Mn: CdO films are possessing cubic crystal structures. SEM and AFM studies reveal that the grain size and roughness of the films are increased with increasing Mn doping concentration. Optical transmittance spectra of the CdO film decreases with increasing doping concentration of manganese. The optical band gap of the films decreases from 2.42 eV to 2.08 eV with increasing concentration of manganese. A minimum resistivity of 1.11×10⁻³ Ω cm and maximum mobility of 20.77 cm² V⁻¹ s⁻¹ is achieved for 1 wt% of manganese doping.     

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.     

Substrate temperature dependent studies on properties of chemical spray pyrolysis deposited CdS thin films for solar cell applications

Thin films of CdS have been prepared by chemical spray pyrolysis by spraying precursor solution directly onto soda lime glass(SLG) substrates. Influence of substrate temperature on structural, optical, morphological and electrical properties have been investigated by using various techniques such as low angle X-ray diffraction(XRD), Raman spectroscopy, X-ray photoelectron spectroscopy(XPS), field emission scanning electron microscopy(FESEM), atomic force microscopy(AFM), transmission electron microscopy(TEM), UV-visible spectroscopy photoluminescence(PL) spectroscopy etc. Formation of CdS has been confirmed by low angle XRD, Raman spectroscopy and XPS analysis. XRD pattern showed that CdS films are polycrystalline, have hexagonal structure and prefer orientation of crystallites shifts from(101) to(002) with increase in substrate temperature. Raman spectroscopy revealed that exciton-phonon coupling depends on substrate temperature and hence on crystallite size. Optical band gap increased from 2.43 to 2.99 eV when substrate temperature increased from 325 to 475℃. Transmittance of the film also showed an increasing trend from ~52% to ~80% with increase in substrate temperature. Such high band gap and transmittance values of CdS films prepared at 475℃ make it a useful window material in CdS/CdTe and CdS/Cu₂S heterojunction solar cells.     

Study on structural,morphological, electrochemical and corrosion properties of mesoporous RuO2 thin films prepared by ultrasonic spray pyrolysis for supercapacitor electrode application

RuO₂ samples were deposited on stainless steel at 723 K by an ultrasonic spray pyrolysis technique using 0.005 M RuCl₃.nH₂O as a precursor solution. XRD analysis confirms the amorphous nature of the deposited samples. Raman studies confirm the formation of RuO₂ phase. SEM, AFM and HRTEM morphologies illustrate uniform spherical granular type morphology of hydrophilic nature. BET study confirms mesoporous nature. RuO₂ phase formation is also confirmed by using XPS analysis. All electrochemical characterizations of the as deposited electrodes were carried out in 0.5 M H₂SO₄ electrolyte. Optimized electrode shows maximum specific capacitance 2192 F/g at 2 mV/sec. The achieved maximum values of specific energy (SE) specific power (SP) and columbic efficiency (η) calculated by using galvanostatic charge-discharge method are 61.12 Wh/Kg, 114.94 kW/Kg and 72.34% respectively. The obtained corrosion rate is ~ 0.1171(mm/year) which is very less than reported values.     

Solution flow rate influence on properties of copper oxide thin films deposited by ultrasonic spray pyrolysis

The present work is an investigation of the solution flow rate influence on copper oxide (CuO) thin film properties deposited by ultrasonic spray pyrolysis. A set of CuO thin films were deposited, with various solution flow rates, on glass substrate at 300 °C. The precursor solution is formed with copper salt dissolution in distilled water with 0.05 molarity. The solution flow rate was ranged from 10 to 30 ml/h. Films composition and structure were characterized by means of XRD (X Rays diffraction) and Raman scattering. The optical properties were studied using UV–visible spectroscopy. The electrical conductivity, carrier mobility and concentration were determined by Hall Effect measurements. The obtained results indicate that flow rate is a key parameter controlling CuO films growth mechanism and their physical properties. The prepared films are mainly composed with a CuO monophase, the crystallite size is reduced with increasing the flow rate. A ZnO/CuO heterojunction structure has been realized and its rectifying behavior is tested.     

Raman spectroscopic study of In2S3 films prepared by spray pyrolysis

Indium sulfide (In₂S₃) thin films are of interest as buffer layers in chalcopyrite absorber based solar cells; and as media providing two-photon absorption for intermediate-band solar cells. We investigated the suitability of chemical spray pyrolysis (CSP) for growing In₂S₃ thin films in a structural order where indium atoms are preferentially in the octahedral sites. We sprayed aqueous or alcoholic solutions of indium chloride (InCl₃) and thiourea (SC(NH₂)₂) precursors onto a substrate with surface temperatures (T_S) of 205, 230, 275 and 320 °C. The as-deposited films grown from aqueous solutions were annealed in 5% H₂S containing atmosphere at 500 °C. We used Raman spectroscopy, X-ray diffraction and Energy Dispersive X-ray spectroscopy to evaluate the effect of growth temperature and the effect of annealing on the film structure and stoichiometry. The use of alcoholic solvent instead of aqueous allows us to use much lower T_S while preserving the quality of the β-In₂S₃ films obtained. Similarly, films with increased stoichiometry and quality are present at a higher T_S; and when annealed. The annealing of the films grown at T_S of 205 °C results in a much higher gain of the crystal quality compared to the gain when annealing the films grown at T_S of 320 °C, although the quality remain higher when deposited at T_S of 320 °C. Simultaneously with the increase of the film quality, there is a sign of increased quality of the crystal ordering with indium in the octahedral sites. Such a crystal ordering favor the use of CSP deposited In₂S₃ films in the intermediate band solar cells.     

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...     

Effect of deposition conditions on the physical properties of SnxSy thin films prepared by the spray pyrolysis technique

Tin sulfide thin films (Sn_xS_y) with an atomic ratio of y/x = 0.5 have been deposited on a glass substrate by spray pyrolysis. The effects of deposition parameters, such as spray solution rate (R), substrate temperature (T_s) and film thickness (t), on the structural, optical, thermo-electrical and photoconductivity related properties of the films have been studied. The precursor solution was prepared by dissolving tin chloride (SnCl₄, 5H₂O) and thiourea in propanol, and Sn_xS_y thin film was prepared with a mole ratio of y/x = 0.5. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis spectroscopy. It is indicated that the XRD patterns of Sn_xS_x films have amorphous and polycrystalline structures and the size of the grains has been changed from 7 to 16 nm. The optical gap of Sn_xS_x thin films is determined to be about 2.41 to 3.08 eV by a plot of the variation of (αhν)² versus hν related to the change of deposition conditions. The thermoelectric and photo-conductivity measurement results for the films show that these properties are depend considerably on the deposition parameters.     

不同离子比的锰钴镍薄膜材料结构和电学性能

采用磁控溅射法分别制备了不同组分的Mn-Co-Ni-O(MCNO)薄膜材料。通过对材料结构分析,发现在Mn离子数目不变的情况下,随着Co离子的增加,晶粒尺寸逐渐增大,且晶格常数先增大后减小;在Co离子数目不变的情况下,随着Mn离子的增加,薄膜的择优生长晶面由(311)不晶面向(400)晶面转变。对电学性能测试进行分析,可知薄膜材料既有Mn离子的导电机制,也有Co离子的导电机制;Mn_1.2Co_1.5Ni_0.3O₄具有最低的电阻率(235 Ω.cm),具有最高的室温负温度电阻系数︱a₂₉₅︱(4.7%.K_-1)值。