scholarly journals Synthesis of N-CNT/TiO2 composites thin films: surface analysis and optoelectronic properties

2020 ◽  
Vol 183 ◽  
pp. 05002 ◽  
Author(s):  
Hamza Belkhanchi ◽  
Younes Ziat ◽  
Maryama Hammi ◽  
Charaf Laghlimi ◽  
Abdelaziz Moutcine ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Analysis ◽  
Sol Gel ◽  
Careful Analysis ◽  
Optoelectronic Properties ◽  
Spectroscopic Techniques ◽  
Large Area ◽  
Visible Absorption ◽  
Temperature Solution ◽  
Good Agreement

In this study, we have investigated the surface analysis and optoelectronic properties on the synthesis of N-CNT/TiO2 composites thin films, using sol gel method for a dye synthetized solar cell (DSSC) which is found to be simple and economical route. The titanium dioxide based solar cells are an exciting photovoltaic candidate; they are promising for the realization of large area devices. That can be synthetized by room temperature solution processing, with high photoactive performance. In the present work, we stated comparable efficiencies by directing our investigation on obtaining Sol Gel thin films based on N-CNT/TiO2, by dispersing nitrogen (N) doped carbon nanotubes (N-CNTs) powders in titanium tetraisopropoxyde (TTIP). The samples were assessed in terms of optical properties, using UV—visible absorption spectroscopic techniques. After careful analysis of the results, we have concluded that the mentioned route is good and more efficient in terms of optoelectronic properties. The gap of “the neat” 0.00w% N-CNT/TiO2 is of 3eV, which is in a good agreement with similar gap of semiconductors. The incorporated “w%NCNTs” led to diminishing the Eg with increasing N-CNTs amount. These consequences are very encouraging for optoelectronic field.

Low-temperature solution-processed sol-gel K-rich KNN thin films for flexible electronics

MRS Advances ◽  
2018 ◽  
Vol 3 (5) ◽  
pp. 269-275 ◽  
Author(s):  
Rajinder Singh Deol ◽  
Meenal Mehra ◽  
Bhaskar Mitra ◽  
Madhusudan Singh
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Low Temperature ◽  
Sol Gel ◽  
Large Area ◽  
Solution Processed ◽  
X Ray ◽  
Force Microscopy ◽  
Temperature Solution ◽  
Piezoelectric Constants

ABSTRACTSputtered lead-free piezoelectric materials like potassium sodium niobate (K1-xNaxNbO3 or KNN) have received significant technological interest in recent years in light of several reports of piezoelectric constants comparable to lead zirconium titanate (PZT). Potential applications include self-powered sensors, actuators, and low acoustic impedance transducers. For large area printed applications, it is vital to develop low-temperature solution processed deposition methods. In this work, sol-gel synthesis of K-rich (70:30) KNN was carried out under an argon atmosphere, using acetate precursors, followed by precipitation of white KNN powder upon careful drying. Powder X-ray diffraction (XRD) scans of the product with a Cu Kα source after calcination revealed a dominant (110) peak, accompanied by smaller (100) and (010) peaks, in agreement with published standard KNN data. The composition of K-rich phase was confirmed using energy dispersive X-ray spectroscopy (EDX). To produce thin films, the sol was spin coated on a surface-treated Au-coated Si substrate, followed by slow annealing to obtain low surface roughness films (RMS roughness ﹤∼10 nm) of thickness ∼200 nm after solvent removal. Atomic force microscopy (AFM) scans revealed an unremarkable amorphous film. However, deposition of the sol on the Au-coated backside of Si wafer under similar processing conditions revealed limited polycrystalline film formation observed using optical profilometry. Thin film XRD measurements of the deposited film reveal orthorhombic phase growth of KNN, though the unannealed film was more amorphous than the calcined KNN film. Preliminary piezoresponse force microscopy (PFM) scans were used to estimate a piezoelectric constant (d33) ∼ 2.7 pC/N, consistent with the general expectation of lower piezoelectric constants for thin sol-gel films. The highest processing temperature used at any step during the deposition process was 90°C, consistent with the applications involving flexible polyimide substrates. This low-temperature thin-film growth suggests a potential route towards integration of large area piezoelectric generators for environmentally-friendly autonomous flexible sensor applications, with better control of phase and composition during the solution-phase deposition of KNN.

Photo-induced Large Area Growth Of Dielectrics With Excimer Lamps

2000 ◽  
Vol 617 ◽  
Author(s):  
Ian W. Boyd ◽  
Jun-Ying Zhang
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Low Temperature ◽  
Leakage Current ◽  
Sol Gel ◽  
Low Dielectric Constant ◽  
Large Area ◽  
Excimer Lamp ◽  
Low Dielectric ◽  
Current Densities

AbstractIn this paper, UV-induced large area growth of high dielectric constant (Ta2O5, TiO2and PZT) and low dielectric constant (polyimide and porous silica) thin films by photo-CVD and sol-gel processing using excimer lamps, as well as the effect of low temperature LW annealing, are discussed. Ellipsometry, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), UV spectrophotometry, atomic force microscope (AFM), capacitance-voltage (C-V) and current-voltage (I-V) measurements have been employed to characterize oxide films grown and indicate them to be high quality layers. Leakage current densities as low as 9.0×10−8 Acm−2 and 1.95×10−7 Acm−2 at 0.5 MV/cm have been obtained for the as-grown Ta2O5 films formed by photo-induced sol-gel processing and photo-CVD. respectively - several orders of magnitude lower than for any other as-grown films prepared by any other technique. A subsequent low temperature (400°C) UV annealing step improves these to 2.0×10−9 Acm−2 and 6.4× 10−9 Acm−2, respectively. These values are essentially identical to those only previously formed for films annealed at temperatures between 600 and 1000°C. PZT thin films have also been deposited at low temperatures by photo-assisted decomposition of a PZT metal-organic sol-gel polymer using the 172 nm excimer lamp. Very low leakage current densities (10−7 A/cm2) can be achieved, which compared with layers grown by conventional thermal processing. Photo-induced deposition of low dielectric constant organic polymers for interlayer dielectrics has highlighted a significant role of photo effects on the curing of polyamic acid films. I-V measurements showed the leakage current density of the irradiated polymer films was over an order of magnitude smaller than has been obtained in the films prepared by thermal processing. Compared with conventional furnace processing, the photo-induced curing of the polyimide provided both reduced processing time and temperature, A new technique of low temperature photo-induced sol-gel process for the growth of low dielectric constant porous silicon dioxide thin films from TEOS sol-gel solutions with a 172 nm excimer lamp has also been successfully demonstrated. The dielectric constant values as low as 1.7 can be achieved at room temperature. The applications investigated so far clearly demonstrate that low cost high power excimer lamp systems can provide an interesting alternative to conventional UV lamps and excimer lasers for industrial large-scale low temperature materials processing.

Structure and optoelectronic properties of Mg-doped CuFeO2 thin films prepared by sol–gel method

2013 ◽  
Vol 577 ◽  
pp. 658-662 ◽  
Author(s):  
Zanhong Deng ◽  
Xiaodong Fang ◽  
Suzhen Wu ◽  
Yiping Zhao ◽  
Weiwei Dong ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Optoelectronic Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Mg Doped

The morphologies and optoelectronic properties of delafossite CuFeO2 thin films prepared by PEG assisted sol–gel method

2014 ◽  
Vol 71 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Zanhong Deng ◽  
Xiaodong Fang ◽  
Suzhen Wu ◽  
Weiwei Dong ◽  
Jingzhen Shao ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Optoelectronic Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Delafossite Cufeo2

“Square” hysteresis loops in phase-switching Nb-doped lead zirconate stannate titanate thin films

1995 ◽  
Vol 10 (11) ◽  
pp. 2764-2769 ◽  
Author(s):  
C.J. Gaskey ◽  
K.R. Udayakumar ◽  
H.D. Chen ◽  
I.E. Cross
Keyword(s):  
Thin Films ◽  
Electric Fields ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Lead Zirconate ◽  
Slight Variation ◽  
Multichip Modules ◽  
Large Area ◽  
Capacitance Density ◽  
Phase Switching

Niobium-doped lead zirconate stannate titanate thin films have been prepared by a modified sol-gel spin on technique, utilizing the hydrolysis-resistant precursor lead acetylacetonate. Films of compositions in the antiferroelectric tetragonal and antiferroelectric orthorhombic phases were prepared and phase-switched with the application of appropriate electric fields. A distinctly “square” hysteresis response was observed in a low titanium, low tin, orthorhombic composition, with a maximum polarization, Pmax, of 40 μC/cm2 and switching field values of Ef = 175 kV/cm and Ea = 75 kV/cm, while varying degrees of squareness, along with lower polarizations and switching fields, were observed in the higher tin, tetragonal compositions. Electric field-induced strains of up to 0.33% have been measured in the orthorhombic composition, with tunable electromechanical coefficients. Film properties showed only slight variation with electrode size over a range of diameters from 0.8 mm to 6.35 mm; large area electrodes are vital for practical actuator and sensor devices. With a capacitance density of 30–35 μF/cm2, films of the orthorhombic composition are promising as power plane decoupling capacitors in multichip modules.

Sol–gel derived Co3O4 thin films: effect of annealing on structural, morphological and optoelectronic properties

2011 ◽  
Vol 23 (3) ◽  
pp. 772-778 ◽  
Author(s):  
M. A. Chougule ◽  
S. G. Pawar ◽  
P. R. Godse ◽  
R. D. Sakhare ◽  
Shashwati Sen ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Optoelectronic Properties
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