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.     

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.     

Spray pyrolysis of tin selenide thin-film semiconductors: the effect of selenium concentration on the properties of the thin films

Thin films of tin selenide（Sn_xSe_y） with an atomic ratio of r =[y/x]= 0.5,1 and 1.5 were prepared on a glass substrate at T = 470℃using a spray pyrolysis technique.The initial materials for the preparation of the thin films were an alcoholic solution consisting of tin chloride（SnCl₄·5H₂O） and selenide acide（H₂SeO₃）.The prepared thin films were characterized by X-ray diffraction（XRD）,scanning electron microscopy,scanning tunneling microscopy,scanning helium ion microscopy,and UV-vis spectroscopy.The photoconductivity and thermoelectric effects of the Sn_xSe_ythin films were then studied.The Sn_xSe_y thin films had a polycrystalline structure with an almost uniform surface and cluster type growth.The increasing atomic ratio of r in the films,the optical gap,photosensitivity and Seebeck coefficient were changed from 1.6 to 1.37 eV,0.01 to 0.31 and -26.2 to—42.7 mV/K （at T = 350 K）,respectively.In addition,the XRD patterns indicated intensity peaks in r = 1 that corresponded to the increase in the SnSe and SnSe₂ phases.     

Effect of SnCl2 and SnCl4 precursors on SnSx thin films prepared by ultrasonic spray pyrolysis

Thin films of SnS_x, semiconductors, have been successfully synthesized by ultrasonic spray pyrolysis technique, using two precursors namely:tin (Ⅱ) chloride and tin (IV) chloride, respectively. The solutions were prepared by the dilution of different Sn molarities of the two precursors separately. The precursor molarities were varied from 0.04 to 0.07 mol/L, whereas that of S was fixed at 0.1 mol/L. The present work focuses on the effect of the different precursor''s molarities on the nature and the properties of the prepared thin films in order to optimize the growth conditions. X-ray diffraction analysis reveals that the precursor''s molarities alter the grain size of the prepared films, which varied from 8 to 14 nm and from 12 to 16 nm, according to the used precursor. The films analysis by SEM, shows that the SnS₂ films are more dense and smooth than the SnS films. The composition of the elements is analysed with an EDX spectrometer, and the obtained result for M_sn D 0:07 mol/L indicates that the atomic ratio of Sn to S is 51.57:48.43 and 36：64 for films synthesized from the first and second precursors respectively. Electrical measurements show that the conductivity behavior depends on the used precursors and their molarities.     

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.     

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 doping concentration on the properties of bismuth doped tin sulfide thin films prepared by spray pyrolysis

Bismuth doped tin sulfide (SnS:Bi) thin films were deposited onto glass substrates by the spray pyrolysis technique at the substrate temperature of 350 °C. The effect of doping concentration [Bi/Sn] on their structural, optical and electrical properties was investigated as a function of bismuth doping between 0 and 8 at%. The XRD results showed that the films were polycrystalline SnS with orthorhombic structure and the crystallites in the films were oriented along (111) direction. Atomic force microscopy revealed that the particle size and surface roughness of the films increased due to Bi-doping. Optical analysis exhibited the band gap value of 1.40 eV for SnS:Bi (6 at%) which was lower than the band gap value for 0 at% of Bi (1.60 eV). The film has low resistivity of 4.788×10⁻¹ Ω-cm and higher carrier concentration of 3.625×10¹⁸ cm⁻³ was obtained at a doping ratio of 6 at%.     

Title:Spray pyrolysis of tin selenide thin film semiconductor: effect of the selenium concentration on the thin film properties

Thin films of tin selenide (Sn_xSe_y) with an atomic ratio of r=≤[y/x]=0.5, 1 and 1.5 were prepared on a glass substrate at T= 470 ℃ using a spray pyrolysis technique. The initial materials for the preparation of the thin films were an alcoholic solution consisting of tin chloride (SnCl₄·5H₂O) and selenide acide (H₂SeO₃). The prepared thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy, scanning tunneling microscopy, scanning helium ion microscopy, and UV-vis spectroscopy. The photoconductivity and thermoelectric effects of the Sn_xSe_y thin films were then studied. The Sn_xSe_y thin films had a polycrystalline structure with an almost uniform surface and cluster type growth. The increasing atomic ratio of r in the films, the optical gap, photosensitivity and Seebeck coefficient were changed from 1.6 to 1.37 eV, 0.01 to 0.31 and-26.2 to-42.7 mV/K (at T= 350 K), respectively. In addition, the XRD patterns indicated intensity peaks in r=1 that corresponded to the increase in the SnSe and SnSe₂ phases.     

沉积时间对Sn-Mg共掺ZnO薄膜光电性能的影响

采用超声喷雾热解法在石英玻璃衬底上,在衬底 温度为440 ℃,喷嘴到衬底距离为4cm,掺杂原子(Zn∶Mg∶Sn)比例为97.6∶2∶0.4,载气流量为0.8 L/min的固定条件下,制备了不同薄膜沉积时间(5min、 7min、9min、11 min)的Sn-Mg共掺的ZnO薄膜。并用X射线衍射仪 (XRD)、扫描电子显微镜(SEM)、 光致发光谱(PL)、紫外可见分光光度计(UV-VIS)、薄膜测厚仪(SCG-10)和伏安特性曲线(I-V)对 薄膜的结构、表面形貌、发光性能、透过率、膜厚和电学性能进行了一系列表征。当沉积时 间为7min时, XRD表明,薄膜的(101)峰强度最大,择优取向明显。SEM图显示薄 膜表面致密光滑,颗粒均匀,尺寸 最大且形貌最佳。PL谱在372 nm处的发射峰强度最大,峰形最尖锐, 所有薄膜的透过率在可见光区域都 超过了80%,表现出了很好的光透过性能。从薄膜的I- V特性曲线可计算出此时的电阻最小,导电性能最佳。     

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...     

Effect of Pb:S molar ratio in precursor solution on the properties of lead sulphide thin films by ultrasonic spray pyrolysis

In this work, PbS thin films were deposited onto glass substrate at 225 °C by spraying precursor solution prepared with different molar ratio of lead acetate and thiourea as a source of Pb²⁺ and S^2- respectively in order to investigate the effect of Pb:S molar ratio in the precursor solution on the physical properties of PbS thin films. Structural investigations carried out by X-ray diffractometer have shown that all films have fcc cubic structure and the average crystal size increased from 11 nm to 25 nm with the increasing the thiourea ratio in the precursor solution. In order to analyze the surface morphology of PbS thin films, AFM and SEM images were taken and elemental analysis of the films was performed by EDS. Optical transmittance and absorption spectra show that all deposited films have fairly low transmittance and high absorbance in the visible region. Additionally, it was determined that optical band gap of the deposited films were varied between 1.18 eV and 1.37 eV. As a consequence of electrical investigations, it was seen that all films have p-type conductivity and electrical resistivity decreased by increasing thiourea molar ratio in the precursor solution. All examinations have revealed that the molar ratio of lead acetate and thiourea has a significant effect on the physical properties of PbS thin films.     

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.     

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.     

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...     

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.     

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.     

Influences of substrate type on the pH sensitivity of CuS thin films EGFET prepared by spray pyrolysis deposition

Copper sulphide (CuS) thin films were deposited by spray pyrolysis using CuCl₂·2H₂O and Na₂S₂O₃·5H₂O precursors as sources of Cu²⁺ and S^2- respectively, with deionized water as a solvent. Three types of substrates were used for films deposition; glass, tungsten and Si. X-ray measurements of the structural characteristics of the deposited films indicated single phase CuS covellite phase with orientations in the z-axis (001). The presence of oxygen suggested improved pH sensing characteristics. Morphological characterization showed differences in shape and size of CuS crystal structure, which affect the surface-to-volume ratio and surface site density of the substrates. The as-deposited films were used as extended gates of field effect transistor to measure the pH sensitivity for buffer solutions in the set of 2-to-12 step 2; the optimum pH sensitivity was 23.3 mV/pH for CuS/glass membrane. The hysteresis was measured for buffer solutions prepared at pH7-pH4-pH7-pH10-pH7 in order to find its pH response delay; the minimum value was 0.48 mV for glass substrate. Also, the repeatability, stability and reliability of the (CuS) thin films were measured in terms of coefficient of variation (C.V.) with the same setup used for measuring pH sensitivity. Repeatability values of 0.04%, 0.02% and 0.38% were recorded for glass, tungsten and Si, respectively, while stability and reliability values of 0.15%, 0.15% and 0.10% were recorded at pH4, pH7 and pH10, respectively, for glass substrate.     

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 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.     

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.