Influence of Aluminum concentration and substrate temperature on the physical characteristics in chemical sprayed ZnO:Al thin films

MRS Advances ◽  
2017 ◽  
Vol 2 (62) ◽  
pp. 3859-3864
Author(s):  
Erick Velázquez Lozada ◽  
Tetyana Torchynska ◽  
Gabriela M. Camacho González ◽  
Luis Castañeda

The continuous interest in the synthesis and properties study of materials has permitted the development of semiconductor oxides. Zinc oxide (ZnO) with hexagonal wurzite structure is a wide band gap n-type semiconductor and interesting material over a wide range. Chemically sprayed aluminium-doped zinc oxide thin films (ZnO:Al) were deposited on soda-lime glass substrates starting from zinc pentanedionate and aluminium pentanedionate. The influence of both the dopant concentration in the starting solution and the substrate temperature on the composition, morphology, and transport properties of the ZnO:Al thin films were studied. The structure of all the ZnO:Al thin films was polycrystalline, and variation in the preferential growth with the aluminium content in the solution was observed: from an initial (002) growth in films with low Al content, switching to a predominance of (101) planes for heavily dopant regime. The crystallite size was found to decrease with doping concentration and range from 33 to 20 nm. First-order Raman scattering from ZnO:Al, all having the wurtzite structure . The assignments of the E2 mode in ZnO:Al differ from previous investigations. The film composition and the dopant concentration were determined by Auger Electron Spectroscopy (AES); these results showed that the films are almost stoichiometric ZnO. The optimum deposition conditions leading to conductive and transparent ZnO:Al thin films were also found. In this way a resistivity of 0.03 Ω-cm with a (002) preferential growth, were obtained in optimized ZnO:Al thin films.

1995 ◽  
Vol 388 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Yoshikazu Nakamura ◽  
Shigekazu Hirayama ◽  
Yuusaku Naota

AbstractAluminum nitride (AlN) thin films have been synthesized by ion-beam assisted deposition method. Film deposition has been performed on the substrates of silicon single crystal, soda-lime glass and alumin A. the influence of the substrate roughness on the film roughness is studied. the substrate temperature has been kept at room temperature and 473K and the kinetic energy of the incident nitrogen ion beam and the deposition rate have been fixed to 0.5 keV and 0.07 nm/s, respectively. the microstructure of the synthesized films has been examined by X-ray diffraction (XRD) and the surface morphology has been observed by atomic force microscopy(AFM). IN the XRD patterns of films synthesized at both room temperature and 473K, the diffraction line indicating the alN (10*0) can be discerned and the broad peak composed of two lines indicating the a1N (00*2) and a1N (10*1) planes is also observed. aFM observations for 100 nm films reveal that (1) the surface of the films synthesized on the silicon single crystal and soda-lime glass substrates is uniform and smooth on the nanometer scale, (2) the average roughness of the films synthesized on the alumina substrate is similar to that of the substrate, suggesting the evaluation of the average roughness of the film itself is difficult in the case of the rough substrate, and (3) the average roughness increases with increasing the substrate temperature.


2013 ◽  
Vol 291-294 ◽  
pp. 703-707
Author(s):  
Gui Shan Liu ◽  
Hao Na Li ◽  
Xiao Yue Shen ◽  
Zhi Qiang Hu ◽  
Hong Shun Hao

CIGS thin films were deposited on soda lime glass by one-step magnetron sputtering using a single quaternary-CIGS target in stoichiometric proportions. The influences of substrate temperature on the structural, optical, and electrical properties of Cu(In,Ga)Se2 (CIGS) thin films were investigated. The phase structure of CIGS thin films was characterized by X-ray diffraction (XRD). The morphology and thickness of CIGS thin films were observed by Scanning Electron Microscope (SEM). The absorption coefficient of CIGS thin films was measured by Ultraviolet-visible Spectrophotometer. Four-point probe method was used to test the resistivity of CIGS thin films. Based on the results of characterization, the increase in crystallite size of CIGS was found to be significantly noticeable with increasing substrate temperature. UV-vis measurement analysis suggested that CIGS thin films deposited at different substrate temperatures had high absorption coefficient (~104 cm-1) and optical band gap (1.07-1.23 eV). The substrate temperature dependence of the resistivity of the films indicated that the resistivity of the films fall to about 0.5 Ω۰cm as the substrate glass was heated up to 300 °C.


2019 ◽  
Vol 60 (5) ◽  
pp. 1006-1012
Author(s):  
Ali H A Jalaukhan ◽  
Mustafa M A Hussein

Fullerene thin films of about 200 nm thicknesses have been deposited by thermal evaporation method on soda lime glass at substrate temperature 303 and 403K under pressure about 10-5 mbar. This study concentrated on the influence of substrate temperature on the optical properties of C60 thin films within the visible range. Optical characterization has been carried out at room temperature using the absorption spectra, at normal incidence, in range (200-900) nm. The absorption and extinction coefficients of the samples have been evaluated according to the variation in the UV- Visible spectrum. Increasing substrate temperature causes decreasing in optical band gap energy, for direct allowed transitions, and slightly changing in refractive index. This incident was due to the reducing of interatomic intervals, which may be correlating a decrease in the amplitude of atomic vibrations around their equilibrium sites.


2002 ◽  
Vol 721 ◽  
Author(s):  
P. Kuppusami ◽  
K. Diesner ◽  
I. Sieber ◽  
K. Ellmer

AbstractSputtering of aluminium doped zinc oxide thin films from a ceramic ZnO:Al target requires a controlled addition of oxygen to the sputtering atmosphere in order to obtain films with low resistivity and high transparency. In this paper the influence of the oxygen addition and of the substrate temperature on the structural, morphological and electrical properties of ZnO:Al films is investigated. The oxygen addition leads to a minimum resistivity when the oxygen content during sputtering is 0.2%. This small amount of oxygen not only improves the transparency of the films, it also induces to a significant grain growth as revealed by scanning electron microscopy. A further increase of the oxygen content leads to highly resistive films, due to a complete oxidation of the dopant Al. As expected, higher substrate temperatures from about 373 to 673 K improve the of crystallinity and hence the resistivity. The lowest resistivity achieved was about 1.2.10-3 Ωcm. At still higher temperatures the resistivity increases which seems to be due to an outdiffusion of sodium into the ZnO:Al films from the soda lime glass, compensating part of the donors.


2013 ◽  
Vol 275-277 ◽  
pp. 2018-2022 ◽  
Author(s):  
Song Feng ◽  
Rong Ping Li ◽  
Lei Tian ◽  
Kai Zou ◽  
Yong Sheng Liu

Pure CdTe thin films and metal Sb-doped CdTe thin films are prepared on soda lime glass substrates by vacuum evaporation method. The prepared films have a cubic crystal structure with a preferential growth orientation along CdTe (111) crystal orientation. The experimental results show that the film surface doped Sb is more compact and uniform. And doping Sb in pure CdTe thin films significantly enhance the optical absorption and reduce the width of the band gap, which means that the optical absorption range of CdTe thin films can be widened. Finally, on the aspect of electrical properties, the resistivity of the thin films has significantly been lower.


Energetika ◽  
2017 ◽  
Vol 63 (2) ◽  
Author(s):  
Jako Siim Eensalu ◽  
Malle Krunks ◽  
Inga Gromyko ◽  
Atanas Katerski ◽  
Arvo Mere

Herein we present a comparative study on highly transparent, conductive aluminium-doped ZnO (AZO) thin films deposited by pneumatic spray pyrolysis (PSP) of a zinc acetate based solution and a zinc acetylacetonate based solution on soda lime glass. The structural, optical and electrical properties of the films were studied depending on aluminium content in the precursor solution and substrate temperature during deposition (Ts). The solution used to prepare AZO thin films contained 0.2 M zinc acetate or 0.2 M zinc acetylacetonate and aluminium acetylacetonate between 0–15 at.% [Al]/[Zn]. Substrate temperature was varied from 275 to 450 °C. Transmittance and reflectance spectra were recorded by UV-VIS-NIR spectroscopy. Resistivity, mobility and charge carrier density were determined by four point probe measurements in ambient conditions. According to X-ray diffraction analysis, AZO films are highly c-axis oriented until 2–3 at.% [Al]/[Zn] in the spray solution, depending on zinc precursor. Crystallite size is 25–30 nm for AZO films deposited at Ts 400 °C. All AZO films exhibited high average optical transmittance of 76–94% in the visible spectrum 400–800 nm wavelength range. Eg values ranged from 3.32 in undoped ZnO to 3.58 eV in in highly doped AZO films deposited from zinc acetylacetonate due to the formation of secondary AlOx phases. The lowest resistivities were obtained at Ts 400 °C for films deposited from zinc acetate, 3–7.5 at.% [Al]/[Zn] in solution (0.40 Ωcm) and at Ts 400 °C, 3–7.5 at.% [Al]/[Zn] in solution for films deposited from zinc acetylacetonate (0.47 Ωcm).


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Samia Ahmed Nadi ◽  
Puvaneswaran Chelvanathan ◽  
Zaihasraf Zakaria ◽  
Mohammad Mezbaul Alam ◽  
Zeid A. Alothman ◽  
...  

Cu2ZnSnS4(CZTS) thin films were deposited on top of Molybdenum (Mo) coated soda lime glass (SLG) substrates using a single target rf magnetron sputtering technique. The sputtering parameters such as base pressure, working pressure, rf power, argon (Ar) gas flow rate, and deposition time were kept consistent throughout the experiment. The effect of different substrate temperatures, for example, room temperature (RT), 300°C, 350°C, 370°C, 400°C, and 450°C, was analyzed by studying their structural, electrical, and optical properties. As-sputtered films were then annealed at 460°C. X-ray diffraction (XRD) measurement revealed the structure to be kesterite with peak of (112) plane in both annealed and as-sputtered CZTS thin films. The crystallinity of the films improved with the increasing substrate temperature until 370°C. Secondary phases of MoS2,CuxMoSx,CuxSnSx,CuxS, and Cu6MoSnS8(hemusite) were also observed in the annealed CZTS films. Scanning electron microscopy (SEM) shows crystallite size of deposited CZTS thin film to be proportionally related to deposition temperature. The highest surface roughness of 67.318 nm is observed by atomic force microscopy (AFM). The conductivity type of the films was found to be p-type by Hall effect measurement system.


2005 ◽  
Vol 865 ◽  
Author(s):  
P. D. Paulson ◽  
S. H. Stephens ◽  
W. N. Shafarman

AbstractVariable angle spectroscopic ellipsometry has been used to characterize Cu(InGa)Se2 thin films as a function of relative Ga content and to study the effects of Cu off-stoichiometry. Uniform Cu(InGa)Se2 films were deposited on Mo-coated soda lime glass substrates by elemental evaporation with a wide range of relative Cu and Ga concentrations. Optical constants of Cu(InGa)Se2 were determined over the energy range of 0.75–C4.6 eV for films with 0 ≤ Ga/(In+Ga) ≤ 1 and used to determine electronic transition energies. Further, the changes in the optical constants and electronic transitions as a function of Cu off-stoichiometry were determined in Cu-In-Ga-Se films with Cu atomic concentration varying from 10 to 25 % and Ga/(In+Ga) = 0.3. Films with Cu in the range 16–24 % are expected to contain 2 phases so an effective medium approximation is used to model the data. This enables the relative volume fractions of the two phases, and hence composition, to be determined. Two distinctive features are observed in the optical spectra as the Cu concentration decreases. First, the fundamental bandgaps are shifted to higher energies. Second, the critical point features at higher energies become broader suggesting degradation of the crystalline quality of the material.


2021 ◽  
Vol 21 (8) ◽  
pp. 4362-4366
Author(s):  
Ji Yong Hwang ◽  
Chung Wung Bark ◽  
Hyung Wook Choi

The perovskite solar cell is capable of energy conversion in a wide range of wavelengths, from 300 nm to 800 nm, which includes the entire visible region and portions of the ultraviolet and infrared regions. To increase light transmittance of perovskite solar cells and reduce manufacturing cost of perovskite solar cells, soda-lime glass and transparent conducting oxides, such as indium tin oxide and fluorine-doped tin oxide are mainly used as substrates and light-transmitting electrodes, respectively. However, it is evident from the transmittance of soda-lime glass and transparent conductive oxides measured via UV-Vis spectrometry that they absorb all light near and below 310 nm. In this study, a transparent Mn-doped ZnGa2O4 film was fabricated on the incident surface of perovskite solar cells to obtain additional light energy by down-converting 300 nm UV light to 510 nm visible light. We confirmed the improvement of power efficiency by applying a ZnGa2O4:Mn down-conversion layer to perovskite solar cells.


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