scholarly journals Effects of rapid thermal annealing on the properties of room-temperature oxygenated DC sputtered zinc thin films for CZTS solar cells application

2021 ◽  
Vol 47 (2) ◽  
pp. 637-647
Author(s):  
Emmanuel R Ollotu ◽  
Nuru R Mlyuka ◽  
Margaret E Samiji
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Solar Cells ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Room Temperature ◽  
Near Infrared ◽  
Hall Effect Measurement ◽  
Window Layer ◽  
Zno Films

This work investigated the potential to achieve zinc oxide (ZnO) films for Cu2ZnSnS4 (CZTS) solar cells window layer at controlled annealing conditions as a potential approach to address elemental inter-diffusion in CZTS solar cells. This involved rapid thermal annealing (RTA) of room-temperature oxygenated DC sputtered zinc thin films in an ambient of nitrogen gas at different temperatures. Structural, morphological, optical, and electrical properties of these films were determined by X-ray diffractometer, Scanning Electron Microscopy, Ultraviolet-visible-near infrared spectrophotometer, and Hall Effect measurement, respectively. ZnO phases were observed after annealing the films over 150 °C. The films’ grains sizes improved with increasing RTA temperature. An exponential decrease in these films’ resistivity was observed with increasing RTA temperature attaining the lowest value at 300 °C. The bandgap and average solar transmittance of the films increased with increasing RTA temperature achieving values that are potential for applications in CZTS solar cells window layer at RTA temperatures beyond 200 °C. Keywords: Sputtering; Rapid thermal annealing; Zinc oxide; Structural; Opt-electrical

Stability Studies on Optical and Structure Properties of Zinc Oxide Thin Films Exposed to Different Environment

2013 ◽  
Vol 667 ◽  
pp. 549-552
Author(s):  
A.S.M. Rodzi ◽  
Mohamad Hafiz Mamat ◽  
M.N. Berhan ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Zinc Oxide ◽  
Absorption Coefficient ◽  
Near Infrared ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Zno Films ◽  
Zno Thin Film ◽  
Oxide Thin Films

The properties of zinc oxide thin films were prepared by sol-gel spin-coating method have been presented. This study based on optical and electrical properties of ZnO thin film. The effects of annealing temperatures that exposed with two environments properties have been investigated. Environments exposed in room (27°C) and hot (80°C) temperatures which are stored by various days. Solution preparation, thin film deposition and characterization process were involved in this project. The ZnO films were characterized using UV-Vis-NIR spectrophotometer for optical properties. From that equipment, the percentage of transmittance (%) and absorption coefficient spectra were obtained. With two environments showed have different absorption coefficient are reveal and all films have low absorbance in visible and near infrared (IR) region but have high UV absorption properties. From SEM investigations the surface morphology of ZnO thin film shows the particles size become smaller and denser in hot temperatures while in room temperatures have porosity between particles.

Effect of Molarity of Precursor Solution on Nanocrystalline Zinc Oxide Thin Films

2009 ◽  
Vol 293 ◽  
pp. 99-105 ◽  
Author(s):  
Girjesh Singh ◽  
S.B. Shrivastava ◽  
Deepti Jain ◽  
Swati Pandya ◽  
V. Ganesan
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Solar Cells ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Precursor Solution ◽  
Zno Films ◽  
Scale Production ◽  
Transparent Conducting ◽  
Wide Range

During the last two decades, the use of transparent conducting films of non-stoichiometric and doped metallic oxides for the conversion of solar energy into electrical energy has assumed great significance. A variety of materials, using various deposition techniques, has been tried for this purpose [1-3]. Among these various materials, zinc oxide (ZnO) is one of the prominent oxide semiconductors suitable for photovoltaic applications because of its high electrical conductivity and optical transmittance in the visible region of the solar spectrum [4]. Furthermore, thin films of ZnO have shown good chemical stability against hydrogen plasma, which is of prime importance in a-Si:H-based solar-cell fabrication. Thus, zinc oxide can serve as a good candidate for replacing SnO2 and indium tin oxide (ITO) films in Si:H-based solar cells. One of the outstanding features of ZnO is its large excitonic binding energy, i.e. 60meV, leading to the existence of excitons at room temperature and even at higher temperatures [5-8]. These unique characteristics have generated a wide range of applications of ZnO. For example, gas sensors [9], surface acoustic devices [10], transparent electrodes and solar cells. Many techniques are used for preparing the transparent conducting ZnO films, such as RF sputtering [11], evaporation [12], chemical vapour deposition [13], ion beam sputtering [14] and spray pyrolysis [15–18]. Among these, the spray pyrolysis technique has attracted considerable attention due to its simplicity and large-scale production combined with low-cost fabrication. By using this technique, one can produce large-area coatings without any need for ultra-high vacuum. Thus, the capital cost and the production cost of high-quality zinc oxide semiconductor thin films are lowest among all other techniques. In the present work, we have synthesized ZnO films by using the spray pyrolysis technique. A number of films have been prepared by changing the molarity of the precursor solution. The prepared films have been characterized with regard to their structural, morphological and electrical properties.

Characterization of Cuprous Oxide Thin Films for Application in Solar Cells

2019 ◽  
Vol 22 ◽  
pp. 65-73
Author(s):  
Ørnulf Nordseth ◽  
Irinela Chilibon ◽  
Bengt Gunnar Svensson ◽  
Raj Kumar ◽  
Sean Erik Foss ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Cuprous Oxide ◽  
Wavelength Region ◽  
Morphological Properties ◽  
Optical Absorption Coefficient ◽  
Sputter Deposited ◽  
Post Deposition

Cuprous oxide (Cu2O) has a high optical absorption coefficient and favourable electrical properties, which make Cu2O thin films attractive for photovoltaic applications. Using reactive radio-frequency magnetron sputtering, high quality Cu2O thin films with good carrier transport properties were prepared. This paper presents the characteristics of Cu2O thin films that were sputter deposited on quartz substrates and subjected to post-deposition rapid thermal annealing. The thickness of the thin films and the optical constants were determined by ellipsometry spectroscopy (SE). The optical transmittance increased in lower wavelength region after annealing at 900 ̊C in rapid thermal annealing (RTA). The structural and morphological properties of the Cu2O thin films were investigated by electronic scanning microscopy (SEM) and atomic force microscopy (AFM), whereas elemental analysis was performed by X-ray fluorescence spectroscopy (XRF). The carrier mobility, carrier density and film resistivity were changed after post-deposition rapid thermal annealing from respectively ~14 cm2/Vs, ~2.3 x 1015 cm-3 and ~193 Ωcm for the as-deposited Cu2O film to ~49 cm2/Vs, ~5.0 x 1014 cm-3 and ~218 Ωcm for the annealed Cu2O film. The investigation suggests that the sputter-deposited Cu2O thin films have good potential for application as absorber layers in solar cells.

Effect of rapid thermal annealing on texture and properties of pulsed laser deposited zinc oxide thin films

2013 ◽  
Vol 98 ◽  
pp. 149-152 ◽  
Author(s):  
K.C. Sekhar ◽  
S. Levichev ◽  
Koppole Kamakshi ◽  
S. Doyle ◽  
A. Chahboun ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Pulsed Laser ◽  
Oxide Thin Films

Effect of rapid thermal annealing on electrical and optical properties of Ga doped ZnO thin films prepared at room temperature

2006 ◽  
Vol 100 (11) ◽  
pp. 113515 ◽  
Author(s):  
Jong Hoon Kim ◽  
Byung Du Ahn ◽  
Choong Hee Lee ◽  
Kyung Ah Jeon ◽  
Hong Seong Kang ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Room Temperature ◽  
Zno Thin Films ◽  
Electrical And Optical Properties ◽  
Doped Zno

SOLUTION PROCESSING OF CADMIUM SULFIDE BUFFER LAYER AND ALUMINUM-DOPED ZINC OXIDE WINDOW LAYER FOR THIN FILMS SOLAR CELLS

2014 ◽  
Vol 21 (04) ◽  
pp. 1450059 ◽  
Author(s):  
MAHBOOB ALAM ◽  
MOHAMMAD ISLAM ◽  
AMINE ACHOUR ◽  
ANSAR HAYAT ◽  
BILAL AHSAN ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Electrical Resistivity ◽  
Solar Cells ◽  
Annealing Temperature ◽  
Window Layer ◽  
Zno Thin Films ◽  
Bath Composition ◽  
Film Properties ◽  
Aluminum Doped Zinc Oxide

Cadmium sulfide ( CdS ) and aluminum-doped zinc oxide ( Al : ZnO ) thin films are used as buffer layer and front window layer, respectively, in thin film solar cells. CdS and Al : ZnO thin films were produced using chemical bath deposition (CBD) and sol–gel technique, respectively. For CBD CdS , the effect of bath composition and temperature, dipping time and annealing temperature on film properties was investigated. The CdS films are found to be polycrystalline with metastable cubic crystal structure, dense, crack-free surface morphology and the crystallite size of either few nanometers or 12–17 nm depending on bath composition. In case of CdS films produced with 1:2 ratio of Cd and S precursors, spectrophotometer studies indicate quantum confinement effect, owing to extremely small crystallite size, with an increase in Eg value from 2.42 eV (for bulk CdS ) to ~ 3.76 eV along with a shift in the absorption edge toward ~ 330 nm wavelength. The optimum annealing temperature is 400°C beyond which film properties deteriorate through S evaporation and CdO formation. On the other hand, Al : ZnO films prepared via spin coating of precursor sols containing 0.90–1.10 at.% Al show that, with an increase in Al concentration, the average grain size increases from 28 nm to 131 nm with an associated decrease in root-mean-square roughness. The minimum value of electrical resistivity, measured for the films prepared using 0.95 at.% Al in the precursor sol, is ~ 2.7 × 10-4 Ω ⋅ cm. The electrical resistivity value rises upon further increase in Al doping level due to introduction of lattice defects and Al segregation to the grain boundary area, thus limiting electron transport through it.

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