Enhancement of electrical properties of vanadyl phthalocyanine derivative by PCBM

2015 ◽  
Vol 44 (3) ◽  
pp. 148-156 ◽  
Author(s):  
F. Aziz ◽  
K. Sulaiman ◽  
Wissam Khayer Al-Rawi ◽  
Z. Ahmad ◽  
M.H. Sayyad ◽  
...  

Purpose – The purpose of this paper is to investigate the effect of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) on improvement of physical and electrical properties of vanadyl phthalocyanine derivative. The correlation between the physical characteristics of the active layers, comprising vanadyl 2,9,16, 23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO) and PCBM, and the electrical properties of metal/organic/metal devices have been studied. The use of soluble vanadyl phthalocyanine derivative makes it very attractive for a variety of applications due to its tunable properties and high solubility. Design/methodology/approach – The sandwich type structures Al/VOPcPhO/Al and Al/VOPcPhO:PCBM/Al were fabricated by spin casting the active organic layers between the top and bottom (aluminum) electrodes. The stand-alone (VOPcPhO) and composite (VOPcPhO:PCBM) thin films were characterized by X-ray diffraction, atomic force microscopy, UV/Vis and Raman spectroscopy. The electronic properties of the metal/organic/metal devices were studied using current-voltage (I-V) characteristics in dark at room temperature. Findings – The values of barrier height for Al/VOPcPhO/Al and Al/VOPcPhO:PCBM/Al devices were obtained from the forward bias I-V curves and were found to be 0.7 eV and 0.62 eV, respectively. The present study indicates that the device employing VOPcPhO:PCBM composite film as the active layer, with better structural and morphological characteristics, results in reduced barrier height at the metal-organic film interface as compared to the one fabricated with the stand-alone film. Research limitations/implications – It is shown that doping VOPcPhO with PCBM improves the crystallinity, morphology and junction properties. Practical implications – The spin coating technique provides a simple, less expensive and effective approach for preparing thin films. The soluble VOPcPhO is conveniently dissolved in a number of organic solvents. Originality/value – The physical properties of the VOPcPhO:PCBM composite thin film and the electrical properties of the composite thin-film-based metal/organic/metal devices have not been reported in the literature, as far as our knowledge is concerned.

2021 ◽  
Author(s):  
Dilber Esra YILDIZ ◽  
A. Karabulut ◽  
I. Orak ◽  
A. Türüt

Abstract The electrical properties of Au/Ti/HfO2/n-GaAs metal/insulating layer/semiconductor (MIS) contact structures were analyzed in detail by the help of capacitance-voltage (C-V) and conductance-voltage (G-V) measurements in the temperature range of 60–320 K. The HfO2 thin film layer was obtained by atomic layer deposition technique (ALD). The main electrical parameters such as ideality factor (n) and barrier height (ΦB0) were determined for Au/Ti/n-GaAs and Au/Ti/HfO2/n-GaAs diodes using current-voltage (I-V) measurement at 300 K. The values of these parameters are 1.07 and 0.77 eV for the reference (Au/Ti/n-GaAs) diode, and 1.30 and 0.94 eV for the Au/Ti/HfO2/n-GaAs MIS diode, respectively. An interfacial charge density value of Qss= 4.14x1012 Ccm− 2 for the MIS diode was calculated from the barrier height difference of ΔΦ=0.94-0.77=0.17 V. Depending on these results, the temperature dependent C-V and G-V plots of the device were also investigated. The series resistance (Rs), phase angle, the interface state density (Dit), the real impedance (Z') and imaginary impedance (Z'') were evaluated using admittance measurements. The C and G values increased, whereas (Z'') and Z decreased with increasing voltage at each temperature. An intersection point being independent of temperature in the G–V curves appeared at forward bias side (≈1.4 V), after this intersection point of the G–V plot, the G values decreased with increasing temperature at a given voltage. The intersection points in total (Z) versus V curves appeared at forward bias side (≈1.7 V). The Nyquist spectra was recorded for the MIS structure showing single semicircular arcs with different diameters depending on temperature.


2013 ◽  
Vol 745-746 ◽  
pp. 599-604 ◽  
Author(s):  
Xue Ying Chen ◽  
Lei Wang ◽  
Jin Bao Xu ◽  
Liang Bian ◽  
Bo Gao

Mn-Co-Ni-O (Mn:Co:Ni=1.74:0.72:0.54, MCN) thin films with single cubic spinel structure were prepared on Si substrates by metal organic solution deposition (MOSD) method at different annealing temperatures. The effects of annealing temperature on the phase component, crystalline microstructure, surface morphology and electrical properties of the MCN thin films were studied. According to the results of x-ray diffraction pattern, the MCN thin film annealed at 650 had spinel structure. Observation with field emission scanning electron microscope (FE-SEM) on the MCN thin films showed that the grain size increased with increasing annealing temperature. The resistance measured at room-temperature was 18.143, 12.457, 2.435 and 3.141MΩ for the MCN thin films annealed at 650, 700, 750 and 800, respectively. The values of thermistor constant (B30/85) and activation energy (Ea) were in the range of 3260-4840K and 0.28-0.42eV, respectively.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1348
Author(s):  
Hiroki Nagai ◽  
Naoki Ogawa ◽  
Mitsunobu Sato

Deep-ultraviolet (DUV) light-transparent conductive composite thin films, consisting of dispersed multiwalled carbon nanotubes (MWCNTs) and SiO2 matrix composites, were fabricated on a quartz glass substrate. Transparent and well-adhered amorphous thin films, with a thickness of 220 nm, were obtained by weak ultraviolet (UV) irradiation (4 mW cm−2 at 254 nm) for more than 6 h at 20−40 °C onto the precursor films, which were obtained by spin coating with a mixed solution of MWCNT in water and Si(IV) complex in ethanol. The electrical resistivity of MWCNT/SiO2 composite thin film is 0.7 Ω·cm, and transmittance in the wavelength region from DUV to visible light is higher than 80%. The MWCNT/SiO2 composite thin film showed scratch resistance at pencil hardness of 8H. Importantly, the resistivity of the MWCNT/SiO2 composite thin film was maintained at the original level even after heat treatment at 500 °C for 1 h. It was observed that the heat treatment of the composite thin film improved durability against both aqueous solutions involving a strong acid (HCl) and a strong base (NaOH).


1988 ◽  
Vol 66 (5) ◽  
pp. 373-375 ◽  
Author(s):  
C. J. Arsenault ◽  
D. E. Brodie

Zn-rich and P-rich amorphous Zn3P2 thin films were prepared by co-evaporation of the excess element during the normal Zn3P2 deposition. X-ray diffraction techniques were used to investigate the structural properties and the crystallization process. Agglomeration of the excess element within the as-made amorphous Zn3P2 thin film accounted for the structural properties observed after annealing the sample. Electrical measurements showed that excess Zn reduces the conductivity activation energy and increases the conductivity, while excess P up to 15 at.% does not alter the electrical properties significantly.


2011 ◽  
Vol 254 ◽  
pp. 167-170 ◽  
Author(s):  
Subodh Srivastava ◽  
Sumit Kumar ◽  
Vipin Kumar Jain ◽  
Y.K. Vijay

In the present work we have reported the effect of temperature on the gas sensing properties of pure Polyaniline (PANI) and Multiwall carbon nanotube (MWNT) doped PANI composite thin film based chemiresistor type gas sensors for hydrogen gas sensing application. PANI and MWNT doped PANI composite were synthesized by in situ chemical oxidative polymerization of aniline using ammonium persulfate in an acidic medium. The thin sensing film of chemically synthesized PANI and MWNT doped PANI composite were deposited onto finger type Cu-interdigited electrodes using spin cast technique to prepared chemiresistor type gas sensor. The electrical properties of these composite thin films were characterized by I-V measurements as function of temperature. The I-V measurement revealed that conductivity of composite thin films increased as the temperature increased. The changes in resistance of the composite thin film sensor were utilized for detection of hydrogen gas. It was observed that at room temperature, MWNT doped PANI composite sensor shows higher response value and sensitivity with good repeatability in comparison to pure PANI thin film sensor. It was also observed that both PANI and MWNT doped PANI composite thin film based sensors showed unstable behavior as the temperature increased. The surface morphology of these composite thin films has also been characterized by scanning electron microscopy (SEM) measurement.


2021 ◽  
Vol 902 ◽  
pp. 65-70
Author(s):  
Samar Aboulhadeed ◽  
Mohsen Ghali ◽  
Mohamad M. Ayad

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.


2021 ◽  
Vol 16 (2) ◽  
pp. 136-141
Author(s):  
Jingyuan Zhang ◽  
Yusheng Liu ◽  
Jianing Song ◽  
Mu Zhang ◽  
Xiaodong Li

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.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1970 ◽  
Author(s):  
Donghyeon Ryu ◽  
Alfred Mongare

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.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jinyu Ruan ◽  
Chao Yin ◽  
Tiandong Zhang ◽  
Hao Pan

Ferroelectric multilayer films attract great attention for a wide variation of applications. The synergistic effect by combining different functional layers induces distinctive electrical properties. In this study, ferroelectric BaZr0.2Ti0.8O3/PbZr0.52Ti0.48O3/BaZr0.2Ti0.8O3 (BZT/PZT/BZT) multilayer thin films are designed and fabricated by using the magnetron sputtering method, and a LaNiO3 (LNO) seed layer is introduced. The microstructures and electrical properties of the BZT/PZT/BZT films with and without the LNO seed layer are systematically studied. The results show that the BZT/PZT/BZT/LNO thin film exhibits much lower surface roughness and a preferred (100)-orientation growth, with the growth template and tensile stress provided by the LNO layer. Moreover, an enhanced dielectric constant, decreased dielectric loss, and improved ferroelectric properties are achieved in BZT/PZT/BZT/LNO thin films. This work reveals that the seed layer can play an important role in improving the microstructure and properties of ferroelectric multilayer films.


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