An Organic/Inorganic Nanomaterial and Nanocrystal Quantum Dots-Based Multi-Level Resistive Memory Device

A cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dot (QD)-based multi-level memory device with the structure [ITO/PEDOT:PSS/QDs/ZnO/Al:Al2O3/QDs/Al] was fabricated via a spin-coating method used to deposit thin films. Two layers of QD thin films present in the device act as charge storage layers to form three distinct states. Zinc oxide (ZnO) and aluminum oxide (Al2O3) were added to prevent leakage. ZnO NPs provide orthogonality between the two QD layers, and a poly(3,4-ethylenedioxythio-phene): poly(styrenesulfonate) (PEDOT:PSS) thin film was formed for effective hole injection from the electrodes. The core/shell structure of the QDs provides the quantum well, which causes the trapping of injected charges. The resistance changes according to the charging and discharging of the QDs’ trap site and, as a result, the current through the device also changes. There are two quantum wells, two current changes, and three stable states. The role of each thin film was confirmed through I–V curve analysis and the fabrication conditions of each thin film were optimized. The synthesized QDs and ZnO nanoparticles were evaluated via X-ray diffraction, transmission electron microscopy, and absorbance and photoluminescence spectroscopy. The measured write voltages of the fabricated device were at 1.8 and 2.4 V, and the erase voltages were −4.05 and −4.6 V. The on/off ratio at 0.5 V was 2.2 × 103. The proposed memory device showed retention characteristics of ≥100 h and maintained the initial write/erase voltage even after 200 iterative operations.

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PREPARATION AND CHARACTERIZATION OF POLYVINYL ALCOHOL THIN FILMS FOR ORGANIC THIN FILM TRANSISTORS AND BIOMEDICAL APPLICATIONS

Kongunadu Research Journal ◽

10.26524/krj264 ◽

2018 ◽

Vol 5 (2) ◽

pp. 16-18

Author(s):

Chandar Shekar B ◽

Ranjit Kumar R ◽

Dinesh K.P.B ◽

Sulana Sundar C ◽

Sunnitha S ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Thin Film Transistors ◽

Gravimetric Method ◽

Dip Coating ◽

Organic Thin Film Transistors ◽

Poly Vinyl Alcohol ◽

Organic Thin Film ◽

Glass Substrates ◽

Coating Method

Thin films of poly vinyl alcohol (PVA) were prepared on pre-cleaned glass substrates by Dip Coating Method. FTIR spectrum was used to identify the functional groups present in the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA.The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The thickness of the prepared thin films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD20) and cross checked by gravimetric method. XRD spectra indicated the amorphous nature of the films.Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. The observed surface morphology indicated that these films could be used as dielectric layer in organic thin film transistors and as drug delivery system for wound healing.

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A Novel Ethanol-Based Non-Particulate Ink for Spin-Coating Cu2ZnSnS4 Thin Film

Journal of Nanoelectronics and Optoelectronics ◽

10.1166/jno.2021.2919 ◽

2021 ◽

Vol 16 (2) ◽

pp. 136-141

Author(s):

Jingyuan Zhang ◽

Yusheng Liu ◽

Jianing Song ◽

Mu Zhang ◽

Xiaodong Li

Keyword(s):

Thin Film ◽

Thin Films ◽

Electrical Properties ◽

Spin Coating ◽

Treatment Temperature ◽

Coated Film ◽

Coating Method ◽

Pre Treatment ◽

Cu2znsns4 Thin Film ◽

Czts Thin Films

The Cu2ZnSnS4 (CZTS) thin films were fabricated by the direct solution coating method using a novel non-particulate ink. The ink was formulated using ethanol as the solvent and 1,2-diaminopropane as the complex-ing agent. The pure phase kesterite films with good crystallinity, large-sized crystals and excellent electrical properties were prepared by the spin-coating deposition technique using the homogeneous and air-stable ink. It was found that the subsequent pre-treatment temperature had an influence on the film crystallinity and electrical properties. The best film was obtained by pre-treating the spin-coated film at 250 °C, and then post-annealing at 560 °C. The film shows a narrow bandgap of 1.52 eV and excellent electrical properties, with a resistivity of 0.07 Ocm, carrier concentration of 3.0 x 1017 cm-3, and mobility of 4.15 cm2 V-1 s-1. The novel non-particulate ink is promising for printing high quality CZTS thin films as absorber layers of thin film solar cells.

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Preparation and Electrical Conductivity Measurement of LiSbO3Thin Films

MRS Proceedings ◽

10.1557/proc-453-617 ◽

1996 ◽

Vol 453 ◽

Cited By ~ 1

Author(s):

K. Ozawa ◽

Y. Sakka ◽

M. Amano

Keyword(s):

Thin Film ◽

Thin Films ◽

Electrical Conductivity ◽

Sol Gel ◽

Conductivity Measurement ◽

Precursor Film ◽

Electrical Conductivity Measurement ◽

Air Atmosphere ◽

Coating Method ◽

Order Of Magnitude

AbstractLiSbO3thin films have been prepared by the sol-gel process with metal alkoxides using a spin-coating method. The (Oll)-oriented and randomly oriented LiSbO3thin films are obtained by the precursor film crystallizing under an atmosphere of a flowing mixture of water vapor and oxygen, and an air atmosphere, respectively. The two different atmospheres also affect the crystallization temperature of the films. The electrical conductivity of the (Oll)-oriented LiSbO3thin film is approximately one order of magnitude larger than that of the randomly oriented LiSbO3thin film in the temperature range of 380 to 600°C.

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Study on the Optimization of Cu-Zn-Sn-O to Prepare Cu2ZnSnS4 Thin Film via a Nano Ink Coating Method

Frontiers in Chemistry ◽

10.3389/fchem.2021.675642 ◽

2021 ◽

Vol 9 ◽

Author(s):

Qian Li ◽

Jinpeng Hu ◽

Yaru Cui ◽

Juan Wang ◽

Jinjing Du ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Ball Milling ◽

Spin Coating ◽

Thin Film Solar Cells ◽

Czts Thin Film ◽

Sem Images ◽

Coating Method ◽

Cu2znsns4 Thin Film ◽

Influence Of Ph

To reduce the formation of the impurity phase, a buffer volume can be used to expands and smooths the surface of Cu2ZnSnS4(CZTS) thin film. In this study, a Cu-Zn-Sn-O(CZTO) precursor was synthesized through the process of coprecipitation-calcination-ball milling-spin coating. The influence of pH, temperature, and PVP on the constituent of hydroxides was investigated in the process of coprecipitation. Cu-Zn-Sn-O with appropriate compositions could be obtained by regulating the temperature and preservation time of the calcination stage. After ball milling to form a nano ink, and then spin coating, SEM images proved the generation of CZTO precursors, which effectively promoted the formation of Cu2ZnSnS4 thin films. Finally, the phase, microstructure, chemical composition, and optical properties of the Cu2ZnSnS4 thin films prepared by sulfurized annealing CZTO precursors were characterized by EDX, XRD, Raman, FESEM, Hall effect, and UV methods. The prepared CZTS thin film demonstrated a band gap of 1.30 eV, which was suitable for improving the performance of CZTS thin film solar cells.

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Broadband Cavity Enhanced Absorption Spectroscopy of thin films of haemoglobin

Al-Mustansiriyah Journal of Science ◽

10.23851/mjs.v30i2.592 ◽

2019 ◽

Vol 30 (2) ◽

pp. 67

Author(s):

Noora Sh. Oraha Qas Nouna ◽

Asmaa S. Al-Ragehey ◽

Saad N. Ibrahim

Keyword(s):

Thin Film ◽

Thin Films ◽

Absorption Spectroscopy ◽

Glass Substrate ◽

Enhanced Absorption ◽

Cavity Enhanced Absorption Spectroscopy ◽

Bovine Haemoglobin ◽

Coating Method ◽

Number Of Passes ◽

Glass Microscope

In this study, a sensitive technique (Broadband Cavity Enhanced Absorption Spectroscopy (BBCEAS)) is employed for measuring the absorption of thin films deposited onto a glass substrate. A thin film of the biological solution such as Lyophilied Bovine haemoglobin is deposited on glass microscope coverslips. Drop coating method was used to deposit a thin film over the microscope coverslips. The number of passes is calculated: 612 passes for the high reflectivity mirror were obtained. The best measurements are made with the mirror set of reflectivity of (R≥ 0.99) which produced an αmin value of 0.0043 cm-1 and LOD of 1.9×10-7M.

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Effect of Bi dopant on morphological and optical properties of ZnO semiconductor films produced by the sol-gel spin coating process

Materials Testing ◽

10.1515/mt-2020-0123 ◽

2021 ◽

Vol 63 (8) ◽

pp. 778-782

Author(s):

Tülay Yıldız ◽

Nida Katı ◽

Kadriye Yalçın

Keyword(s):

Thin Film ◽

Thin Films ◽

Surface Roughness ◽

Optical Properties ◽

Spin Coating ◽

Sol Gel ◽

Zno Thin Film ◽

Spin Coating Method ◽

Coating Method ◽

Doped Zno

Abstract In this study, undoped semiconductor ZnO thin film and Bi-doped ZnO thin films were produced using the sol-gel spin coating method. By changing each parameter of the spin coating method, the best conditions for the formation of the film were determined via the trial and error method. When the appropriate parameter was found, the specified parameter was applied for each film. The structural, superficial, and optical properties of the films produced were characterized via atomic force microscope (AFM), UV-visible spectroscopy, and Fourier transform infrared (FTIR), and the effects of Bi dopant on these properties were investigated. When the morphological properties of the undoped and Bi-doped ZnO films were examined, it was observed that they had a structure in a micro-fiber shape consisting of nanoparticles. When the surface roughness was examined, it was observed that the surface roughness values became larger as the rate of Bi dopant increased. By examining the optical properties of the films, it was determined that they were direct band transition materials and Bi-doped thin films were involved in the semiconductor range. In addition, optical properties changed positively with Bi dopant. Since Bi-doped ZnO thin film has a wide bandgap and good optical properties, it is a material that can be used in optoelectronic applications.

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Annealing Effect on Morphology Optical and Crystallographic Properties of Solution-Based Cu2ZnSnS4 Thin Films

Advanced Science Engineering and Medicine ◽

10.1166/asem.2020.2535 ◽

2020 ◽

Vol 12 (3) ◽

pp. 388-391

Author(s):

Raees A. Gani Shaikh ◽

Sagar A. More ◽

Gauri G. Bisen ◽

Sanjay S. Ghosh

Keyword(s):

Thin Film ◽

Thin Films ◽

Grain Size ◽

Optical Properties ◽

Sol Gel ◽

Crystallographic Structure ◽

Sem Images ◽

Promising Alternative ◽

Coating Method ◽

Czts Thin Films

CZTS chalcopyrite semiconductor has received attention as a promising alternative as an absorber in thin-film solar cells because of the high absorption coefficient, direct bandgap (1.5 eV), nontoxic elements and sustained high electrical and optical properties. In the present work, CZTS thin film has been developed by the sol–gel spin coating method by thermal decomposition of metal ions and thiourea complexes under ambient environment. Annealing study of the above prepared CZTS thin films has been performed. The prepared CZTS samples were annealed at different temperatures 250 °C, 275 °C, 300 °C, and 325 °C respectively. Crystallographic structure, surface morphology, and optical properties were studied. XRD pattern shows the kesterite structure of the films with characteristics peaks for planes (112), (200), (220), and (312). Crystallite size, strain and dislocation densities were calculated. Sample annealed at 300 °C shows the most intense XRD peak and hence larger grain size. Grain size tends to increase as the annealing temperature increases up to 300 °C. At 325 °C SEM images show that cracks are formed in the film. At lower temperatures uniform, homogenous, smooth and densely packed films are formed. Raman spectroscopy is used to determine phase purity because many of binary and ternary chalcogenides show XRD peaks at similar positions to that of CZTS. A single peak at 336 cm–1 shows the pure kestrite phase of CZTS for all films.

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Retention Characteristics of CBTi144 Thin Films Explained by Means of X-Ray Photoemission Spectroscopy

Advances in Materials Science and Engineering ◽

10.1155/2010/710269 ◽

2010 ◽

Vol 2010 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

G. Biasotto ◽

A. Z. Simões ◽

C. S. Riccardi ◽

M. A. Zaghete ◽

E. Longo ◽

...

Keyword(s):

Thin Films ◽

Polar Axis ◽

Photoemission Spectroscopy ◽

X Ray Diffraction ◽

Axis Orientation ◽

X Ray ◽

Si Substrates ◽

Transmission Electron ◽

Coating Method ◽

Retention Characteristics

CaBi4Ti4O15(CBTi144) thin films were grown on Pt/Ti/SiO2/Si substrates using a soft chemical solution and spin-coating method. Structure and morphology of the films were characterized by the X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman analysis, X-ray photoemission spectroscopy (XPS), and transmission electron microscopy (TEM). The films present a single phase of layered-structured perovskite with polar axis orient. Thea/b-axis orientation of the ferroelectric film is considered to be associated with the preferred orientation of the Pt bottom electrode. XPS measurements were employed to understand the nature of defects on the retention behavior of CBTi144 films. We have observed that the main source of retention-free characteristic of the capacitors is the oxygen environment in the CBTi144 lattice.

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Electrical and Structural Properties of TiO2 Thin Film Prepared at Different Annealing Temperatures by Sol-Gel Spin-Coating Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.667.371 ◽

2013 ◽

Vol 667 ◽

pp. 371-374 ◽

Cited By ~ 2

Author(s):

M. Basri ◽

Mohd Nor Asiah ◽

Mohd Khairul bin Ahmad ◽

Mohamad Hafiz Mamat ◽

Mohamad Rusop Mahmood

Keyword(s):

Thin Film ◽

Thin Films ◽

Structural Properties ◽

Spin Coating ◽

Sol Gel ◽

Annealing Treatment ◽

Tio2 Thin Films ◽

Glass Substrates ◽

Annealing Temperatures ◽

Coating Method

Titanium Dioxide (TiO2) thin films have been prepared on glass substrates by using sol-gel method and spin-coating technique. The samples have been annealed at temperatures of 350°C ~ 500oC. The electrical and structural properties of the thin films due to the changes of annealing treatment process were investigated by 2 point probes I-V measurement and X-ray Diffraction (XRD) respectively. The result show that resistivity of the thin film decreased with annealing temperatures. XRD characterization indicates crystalline structure of TiO2 thin films improved as annealed at higher temperatures.

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Mechanical Behavior of Spin-Coated Sb2S3 light Absorption Thin Films

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2021.59.1.1 ◽

2021 ◽

Vol 59 (1) ◽

pp. 1-7

Author(s):

Mao Zhang ◽

Dayoung Yoo ◽

Youngseon Jeon ◽

Dongyun Lee

Keyword(s):

Thin Film ◽

Thin Films ◽

Mechanical Properties ◽

Light Absorption ◽

Indentation Test ◽

Flexible Devices ◽

Heat Treated ◽

Coating Method ◽

Continuous Stiffness Measurement ◽

Fto Glass

To measure the mechanical properties of Sb2S3, a two-component compound semiconductor used in the light absorption layer of a solar cell, Sb2S3 thin films were formed on FTO glass using the spin coating method. The spin-coated Sb2S3 thin films were heat-treated at 200 <sup>o</sup>C in an Ar atmosphere for up to 1 hour to form a thin film with continuous crystalline structures. A nanoindentation system was used to measure the mechanical properties of the spin-coated Sb2S3 thin films, and the phenomena appearing during indentation were analyzed. We used the continuous stiffness measurement (CSM) technique, and Young's modulus and hardness measured with the indentation depth of 250 nm were about 53.1 GPa and 1.43 GPa, respectively. The results were analyzed and compared with literature values, which varied from 40 GPa for the nanowire forms of Sb2S3 to 117 GPa, based upon simulation results. Since there are few studies on the mechanical properties of spin-coated Sb2S3 thin films, the results of this study are worthwhile. Besides, we observed that the Sb2S3 thin film had a little brittleness in the indentation test at higher load, and the microstructure was pushed around the indenter depending on the degree of bonding to the FTO glass substrate. This is a matter to be considered when making flexible devices in the future.

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