INSIGHT INTO STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF COBALT OXIDE Co3O4 THIN FILM

2019 ◽  
Vol 27 (04) ◽  
pp. 1950134
Author(s):  
K. M. E. BOUREGUIG ◽  
H. TABET-DERRAZ ◽  
T. SEDDIK
Keyword(s):  
Thin Film ◽  
Electrical Resistivity ◽  
Electrical Properties ◽  
Spherical Shape ◽  
Experimental Investigations ◽  
Spray Pyrolysis Method ◽  
Optical And Electrical Properties ◽  
Forbidden Transition ◽  
Scherrer Formula ◽  
Increasing Temperature

In the present paper, experimental investigations on structural, morphological, optical and electrical properties of Co3O4 thin film deposited by spray pyrolysis method are reported. Using the interplanar spacing of the XRD reflection and Scherrer formula, respectively, we observed that the obtained films identified crystallize in the cubic spinel structure with [Formula: see text] nm and [Formula: see text] nm. From the SEM picture, a dense grain in the morphology of Co3O4 is detected which has a uniform spherical shape. In addition, transmittance, absorbance, optical bandgap and extinction coefficient of the film versus incident photon energy were calculated. We found that Co3O4 film has a direct bandgap and direct forbidden transition varying from 1.69 eV to 2.85 eV and 1.62 eV to 1.88 eV, respectively. Further, the variation of (DC) electrical resistivity with temperature (from the room temperature of 27∘C to 350∘C) shows that the electrical resistivity was decreased with increasing temperature indicating a semiconducting transport behavior.

Optical and electrical properties of solution processable TiOx thin films for solar cell and sensor applications

2011 ◽  
Vol 1352 ◽  
Author(s):  
Jiguang Li ◽  
Lin Pu ◽  
Mool C. Gupta
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Resistivity ◽  
Refractive Index ◽  
Solar Cells ◽  
Solar Cell ◽  
Electrical Properties ◽  
Thermal Annealing ◽  
Electrical Resistance ◽  
Optical And Electrical Properties

ABSTRACTRecently, few tens of nanometer thin films of TiOx have been intensively studied in applications for organic solar cells as optical spacers, environmental protection and hole blocking. In this paper we provide initial measurements of optical and electrical properties of TiOx thin films and it’s applications in solar cell and sensor devices. The TiOx material was made through hydrolysis of the precursor synthesized from titanium isopropoxide, 2-methoxyethanol, and ethanolamine. The TiOx thin films of thickness between 20 nm to 120 nm were obtained by spin coating process. The refractive index of TiOx thin films were measured using an ellipsometric technique and an optical reflection method. At room temperature, the refractive index of TiOx thin film was found to be 1.77 at a wavelength of 600 nm. The variation of refractive index under various thermal annealing conditions was also studied. The increase in refractive index with high temperature thermal annealing process was observed, allowing the opportunity to obtain refractive index values between 1.77 and 2.57 at a wavelength 600 nm. The refractive index variation is due to the TiOx phase and density changes under thermal annealing.The electrical resistance was measured by depositing a thin film of TiOx between ITO and Al electrode. The electrical resistivity of TiOx thin film was found to be 1.7×107 Ω.cm as measured by vertical transmission line method. We have also studied the variation of electrical resistivity with temperature. The temperature coefficient of electrical resistance for 60 nm TiOx thin film was demonstrated as - 6×10-3/°C. A linear temperature dependence of resistivity between the temperature values of 20 – 100 °C was observed.The TiOx thin films have been demonstrated as a low cost solution processable antireflection layer for Si solar cells. The results indicate that the TiOx layer can reduce the surface reflection of the silicon as low as commonly used vacuum deposited Si3N4 thin films.

Development of the Structural, Optical, and Electrical Properties of PEDOT:PSS Conducting Polymer Thin Film for Energy Applications

2021 ◽  
Vol 902 ◽  
pp. 65-70
Author(s):  
Samar Aboulhadeed ◽  
Mohsen Ghali ◽  
Mohamad M. Ayad
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Conducting Polymer ◽  
Film Surface ◽  
Volume Ratio ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Optical And Electrical Properties ◽  
Energy Applications

We report on a development of the structural, optical and electrical properties of poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) conducting polymer thin films. The PEDOT:PSS thin films were deposited by a controlled thin film applicator and their physical properties were found to be effectively modified by isopropanol. The deposited films were investigated by several techniques including XRD, UV–Vis, SPM and Hall-effect. Interestingly, by optimizing the PEDOTS:PSS/ISO volume ratio (v:v), we find that the film charge carriers type can be switched from p to n-type with a high bulk carriers concentration reaching 6×1017 cm-3. Moreover, the film surface roughness becomes smoother and reaching a small value of only 1.9 nm. Such development of the PEDOT:PSS film properties makes it very promising to act as an electron transport layer for different energy applications.

scholarly journals Corrugated Photoactive Thin Films for Flexible Strain Sensor

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1970 ◽  
Author(s):  
Donghyeon Ryu ◽  
Alfred Mongare
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Tensile Strain ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Optical And Electrical Properties ◽  
Strain Sensing ◽  
Dc Voltage ◽  
Flexible Strain Sensor

In this study, a flexible strain sensor is devised using corrugated bilayer thin films consisting of poly(3-hexylthiophene) (P3HT) and poly(3,4-ethylenedioxythiophene)-polystyrene(sulfonate) (PEDOT:PSS). In previous studies, the P3HT-based photoactive non-corrugated thin film was shown to generate direct current (DC) under broadband light, and the generated DC voltage varied with applied tensile strain. Yet, the mechanical resiliency and strain sensing range of the P3HT-based thin film strain sensor were limited due to brittle non-corrugated thin film constituents. To address this issue, it is aimed to design a mechanically resilient strain sensor using corrugated thin film constituents. Buckling is induced to form corrugation in the thin films by applying pre-strain to the substrate, where the thin films are deposited, and releasing the pre-strain afterwards. It is known that corrugated thin film constituents exhibit different optical and electronic properties from non-corrugated ones. Therefore, to design the flexible strain sensor, it was studied to understand how the applied pre-strain and thickness of the PEDOT:PSS conductive thin film affects the optical and electrical properties. In addition, strain effect was investigated on the optical and electrical properties of the corrugated thin film constituents. Finally, flexible strain sensors are fabricated by following the design guideline, which is suggested from the studies on the corrugated thin film constituents, and the DC voltage strain sensing capability of the flexible strain sensors was validated. As a result, the flexible strain sensor exhibited a tensile strain sensing range up to 5% at a frequency up to 15 Hz with a maximum gauge factor ~7.

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