Properties of PEDOT:PEG/ZnO/p-Si heterojunction diode

The zinc oxide (ZnO) and poly(3,4-ethylenedioxythiophene) bis-poly(ethyleneglycol) (PEDOT:PEG) films were deposited on p-Si substrate by sputter and spin coating methods, respectively. An organic/inorganic heterojunction diode having PEDOT:PEG/ZnO on p-Si substrate was fabricated. The barrier height (BH) and the ideality factor values for the device were found to be 0.82 ± 0.01 eV and 1.9 ± 0.01, respectively. It has been seen that the value of BH is significantly larger than those of conventional Au/p-Si metal–semiconductor contacts. The PEDOT:PEG/ZnO/p-Si heterostructure exhibits a non-ideal I–V behavior with the ideality factor greater than unity that could be ascribed to the interfacial layer, interface states and series resistance. The modified Norde\u27s function combined with conventional forward I–V method was used to extract the parameters including the barrier height and series resistance. At the same time, the physical properties of ZnO and PEDOT:PEG films deposited by sputter and spin coating technique, respectively, were investigated at room temperature. The obtained results indicate that the electrical parameters of the diode are affected by structural properties of ZnO film and PEDOT:PEG organic film

Nanostructured Al Doped SnO2 Films Grown onto ITO Substrate via Spray Pyrolysis Route

We report on nanostructured films of Al doped tin oxide grown by facile spray pyrolysis route, and their physical properties were investigated. The sprayed films were grown onto indium tin oxide (ITO) substrate at 300 °C from the precursor (SnCl4, 5H2O). The content of Al is kept at 3 % in the solution. Structural, optical, electrical and surface properties were investigated. X-rays pattern reveals polycrystalline structure and SnO2 phase occurence. The visible transmitance exceeds 85 %, the band gap is found to be 3.7 eV. Nanotips were observed by 3D atomic force microscope (AFM) observation. Using the Hall effect measurements system (HMS), the films exhibit very low resistivity found to be 9.85 10 – 5 Ω.cm, a high electron concentration is around 1021 cm – 3, and the mobility reaches the value of 20 cm2/Vs. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2490

Dielectric Properties of Calcium Phosphate Ceramics

Calcium phosphate ceramics with various Ca/P ratios of 1, 2, 3, 4 and 8 were synthesized via sol-gel route. The effects of Ca/P molar ratio on structural, morphological, dielectric and antimicrobial properties were investigated in detail using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy and dielectric measurements. The Ca/P molar ratio significantly affects the crystal structure and phase composition. The crystallite size, lattice parameters and volume of the unit cell were remarkably affected by the change in the Ca/P molar ratio. The microstructure is changed with increasing the Ca/P molar ratio. The relative permittivity and alternating current conductivity gradually decrease for the samples having the Ca/P ratios higher than 2. The dielectric loss decreases gradually with the increase of the molar ratio of Ca/P.DOI: http://dx.doi.org/10.5755/j01.ms.22.1.7222</p

Electrical performance of conducting polymer (SPAN) grown on GaAs with different substrate orientations

This article reports the effect of n-type GaAs substrate orientation, namely (100), (311)A and (311)B, on the electrical properties of sulfonated polyaniline (SPAN)/GaAs heterojunction devices. In addition, the inhomogeneity of the interface between various GaAs substrates and SPAN is investigated in terms of barrier height and ideality factor by performing I–V measurements at different temperatures (20–420K). The I–V results indicate that the value of the rectification ratio (IF/IR) at 0.5V is higher for SPAN/(311)B GaAs samples than for SPAN/(100) GaAs and SPAN/(311)A GaAs samples. Moreover, the barrier height decreases and the ideality factor increases with decreasing temperature for all three heterostructure devices. The high value of mean barrier ˚¯ b of SPAN/(311)B (calculated from the plots of ˚b0 as a function of 1/2kT) confirms that the GaAs substrate orientation results in an increase of barrier homogeneities. Furthermore,the C-V characteristics were obtained at room temperature. The C-V measurements showed that the carrier distributions at the interface and away from the interface in high index (311) GaAs orientations are more uniform and have better barrier homogeneity than those grown on the conventional (100) GaAs substrates

Sn1-xBixO2 and Sn1-xTaxO2 (0 \leq x \leq 0.75): A first-principles study

The structural, elastic, electronic and optical (x = 0) properties of doped Sn1-xBixO2 and Sn1-xTaxO2 (0 \leq x \leq 0.75) are studied by using the first-principles pseudopotential plane-wave method within the local density approximation. The independent elastic constants Cij and other elastic parameters of these compounds have been calculated for the first time. The mechanical stability of the compounds with different doping concentrations has also been studied. The electronic band structure and density of states are calculated and the effect of doping on these properties is also analyzed. It is seen that the band gap of the undoped compound narrowed with dopant concentration which disappeared for x = 0.26 for Bi doping and 0.36 for Ta doping. The materials thus become conductive oxides through the change in the electronic properties of the compound for x \leq 0.75 which may be useful for potential application. The calculated optical properties, e.g. dielectric function, refractive index, absorption spectrum, loss-function, reflectivity and conductivity of the undoped SnO2 in two polarization directions are compared with both previous calculations and measurements. Keywords: Doped SnO2; First-principles; Mechanical properties; Electronic band structure; Optical properties.Comment: 10 pages, 5 figures, added 10 more references, comparison with mearements mad

A kinetic study of mercury(II) transport through a membrane assisted by new transport reagent

Background: A new organodithiophosphorus derivative, namely O-(1,3-Bispiperidino-2-propyl)-4-methoxy phenyldithiophosphonate, was synthesized and then the kinetic behavior of the transport process as a function of concentration, temperature, stirring rate and solvents was investigated.Results: The compound 1 was characterized by elemental analysis, IR, H-1 and P-31 NMR spectroscopies. The transport of mercury(II) ion by a zwitterionic dithiophosphonate 1 in the liquid membrane was studied and the kinetic behavior of the transport process as a function of concentration, temperature, stirring rate and solvents was investigated. The compound 1 is expected to serve as a model liquid membrane transport with mercury(II) ions.Conclusion: A kinetic study of mercury(II) transport through a membrane assisted by O-(1,3-Bispiperidino-2-propyl)4-methoxy phenyldithiophosphonate was performed. It can be concluded that the compound 1 can be provided a general and straightforward route to remove toxic metals ions such as mercury(II) ion from water or other solution