Low-temperature fabrication of VO2 thin film on ITO glass with a Mott transition

2016 ◽  
Vol 09 (05) ◽  
pp. 1650062 ◽  
Author(s):  
Tiegui Lin ◽  
Langping Wang ◽  
Xiaofeng Wang ◽  
Yufen Zhang

Polycrystalline Vanadium dioxide (VO2) thin film can be fabricated on glass substrates by high power impulse magnetron sputtering at a relative high temperature. In order to apply an effective bias voltage on substrate and control the energy of the ions impinged to the substrate, conductive indium-tin oxide (ITO) glass was used as the substrate. UV-visible-near IR transmittance spectra and X-ray diffraction (XRD) patterns of the as-deposited films exhibited that M-VO2 thin film with a metal–insulator transition temperature of 37[Formula: see text]C was fabricated successfully at 300[Formula: see text]C with a bias voltage of [Formula: see text]200[Formula: see text]V, and the calculated average crystalline size of this film was about 12[Formula: see text]nm. XRD patterns at varied temperatures showed that the structural change of MIT of the VO2 thin film was suppressed during the phase transition process, and a pure Mott transition was obtained.

2013 ◽  
Vol 1530 ◽  
Author(s):  
Neha Batra ◽  
Monika Tomar ◽  
Vinay Gupta

ABSTRACTZinc oxide (ZnO) thin film deposited onto indium tin oxide (ITO) coated Corning glass substrates using pulsed laser deposition (PLD) technique has been used as a matrix for realization of an efficient urea biosensor after immobilization of urease (Urs) enzyme onto the surface of ZnO. The bioelectrode (Urs/ZnO/ITO/glass) is found to be exhibiting an enhanced sensitivity of 22μΑmΜ−1cm−2 towards urea over a wide detection range of 5-200 mg/dl. The relatively low value of Michaelis menten constant (Km= 0.94mM) indicates high affinity of the immobilized urease towards the analyte (urea). The prepared biosensor retains 90% of its activity for more than 10 weeks. The observed enhanced response characteristics of bioelectrode are attributed to the growth of the matrix (highly c-axis oriented ZnO thin film) with desired surface morphology and high electron communication feature. The results confirm the promising application of PLD grown ZnO thin film as an efficient matrix for urea detection.


2016 ◽  
Vol 78 (5-8) ◽  
Author(s):  
Khairul Aimi Yusof ◽  
Rohanieza Abdul Rahman ◽  
Muhammad AlHadi Zulkefle ◽  
Sukreen Hana Herman ◽  
Wan Fazlida Hanim Abdullah

Titanium dioxide (TiO2) thin films were fabricated on indium tin oxide (ITO) glass substrates using the spin coating technique and further were implemented as sensing membranes of the extended gate field effect transistor (EGFET) based pH sensor. The as-deposited thin films were annealed at different temperatures from 200 - 600 °C in room ambient for 20 min. The effects of different annealing temperatures on electrical and crystalline properties were analyzed by I-V two point probes measurement and X-ray diffraction respectively. Meanwhile, the surface morphology of thin films was observed by field emission scanning electron microscope (FESEM). We then measured the transfer characteristics (ID-VG) of the TiO2/ITO sensing membrane using a semiconductor parametric device analyzer for sensor characterization. It was found that, TiO2/ITO sensing membrane annealed at 300 °C achieved higher sensitivity and good linearity of 51.48 mV/pH and 0.99415, respectively in the pH buffer solutions of 4, 7, 10, and 12. Thin film annealed at 300 °C gives higher conductivity thin film of 384.62 S/m. We found that the conductivity of TiO2/ITO thin films was proportional with the sensitivity of sensing membrane.  


2012 ◽  
Vol 486 ◽  
pp. 417-421 ◽  
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Jian Quan Qi ◽  
Xuan Wang

Multiferroic La-doped Bi1-xLaxFeO3 thin films were prepared on conductive indium tin oxide (ITO)/glass substrates through a simple sol-gel process. The crystal structure of La-doped Bi1-xLaxFeO3 thin films annealed at different temperature was determined to be rhombohedral of R3m space and free of secondary phases. The grain size of La-doped BiFeO3 thin films tends to become larger and the grain boundary is gradually ambiguous compared to pure BiFeO3. The double remanent polarization 2Pr of Bi0.9La0.1FeO3 thin film annealed at 500°C is 6.66 µC/cm2, which is slightly improved than that of pure BiFeO3 thin film. With the increase of La-doping levels, the dielectric constant is increased and the dielectric loss is obviously decreased.


2013 ◽  
Vol 537 ◽  
pp. 109-113
Author(s):  
Xi Wei Qi ◽  
Xiao Yan Zhang ◽  
Xuan Wang ◽  
Hai Bin Sun ◽  
Jian Quan Qi

A series of Dy doped La and Sc solution of BiFeO3 thin films have been prepared by using spin-coating process on conductive indium tin oxide (ITO)/glass substrates, which a simple sol-gel possess is applied and annealed at 500°C. With the increase of content of Dy, the strongest peak (110) of La and Sc solution BiFeO3 film tends to further broaden. There is no second phase existence within the present Dy doping level. Cross section scanning electron microscope (SEM) pictures revealed that the thickness of BiFeO3 film was about 370 nm. For Dy doping level is 0.05, the maximum double remanent polarization 2Pr of as-prepared BiFeO3 thin film is15.44 μC/cm2. Image of atomic force microscopy indicated that the root-mean-square surface roughness value of as-prepared BiFeO3 thin film is 2.11 nm. The dielectric constant of as-prepared films tends to firstly increase and then decrease with the increase of Dy content


2011 ◽  
Vol 492 ◽  
pp. 202-205 ◽  
Author(s):  
Xi Wei Qi ◽  
Xiao Yan Zhang ◽  
Xuan Wang ◽  
Hai Bin Sun ◽  
Jian Quan Qi

BiFeO3 thin films were spin-coated on conductive indium tin oxide (ITO)/glass substrates by a simple sol-gel possess annealed at 470-590°C. The crystal structure of as-prepared BiFeO3 thin films annealed at different temperature was determined to be rhombohedral of R3m space and free of secondary phases was also confirmed. Cross section scanning electron microscope (SEM) pictures revealed that the thickness of BiFeO3 thin film was about 320 nm. The double remanent polarization 2Pr of BiFeO3 thin film annealed at 500°C is 2.5 μC/cm2 without applied field at room temperature. Image of atomic force microscopy indicated that the root-mean-square surface roughness value of BiFeO3 thin film was 6.13 nm.


2012 ◽  
Vol 538-541 ◽  
pp. 78-82
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Jian Quan Qi ◽  
Xuan Wang ◽  
Huan Huan Chen ◽  
...  

Pure Bi0.9La0.1Fe1-xScxO3 (x = 0, 0.05, 0.10, 0.15, 0.20) (BLFSO) thin films were deposited on conductive indium tin oxide (ITO)/glass substrates through a simple sol-gel process. The effect of Sc doping on the XRD, microstructure, dielectric and ferroelectric properties of BLFO films was studied. Compared to counterparts of Bi0.9La0.1FeO3 (BLFO) film, the grain refinement of all films is obvious. When the value of Sc is 0.15, the double remanent polarization 2Pr is effectively enhanced with the extreme value of 17.7µC/cm2. The dielectric constant exhibits a trends of increase firstly and then decrease with the increase amount of scandium level.


Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 118
Author(s):  
Rodica Ionescu ◽  
Raphael Selon ◽  
Nicolas Pocholle ◽  
Lan Zhou ◽  
Anna Rumyantseva ◽  
...  

Conductive indium-tin oxide (ITO) and non-conductive glass substrates were successfully modified with embedded gold nanoparticles (AuNPs) formed by controlled thermal annealing at 550 °C for 8 h in a preselected oven. The authors characterized the formation of AuNPs using two microscopic techniques: scanning electron microscopy (SEM) and atomic force microscopy (AFM). The analytical performances of the nanostructured-glasses were compared regarding biosensing of Hsp70, an ATP-driven molecular chaperone. In this work, the human heat-shock protein (Hsp70), was chosen as a model biomarker of body stress disorders for microwave spectroscopic investigations. It was found that microwave screening at 4 GHz allowed for the first time the detection of 12 ng/µL/cm2 of Hsp70.


2021 ◽  
Author(s):  
Younes Ziat ◽  
Hamza Belkhanchi ◽  
Maryama Hammi ◽  
Charaf Laghlimi ◽  
A Moutcine

Abstract Recently, the rise of two dimensional amorphous nanostructured thin films have ignited a big interest because of their intriguingly isotropic structural and physical properties leading to potential applications in the nano-optoelectronics. However, according to literature, most of optoelectronic properties are investigated on chalcogenides related heterostructures. This has motivated the present work aiming to provide a new platform for the fabrication, examination of the properties and the applications of 2D nanostructured thin films based on epoxy/silicone blend. Thin films of Epoxy/Silicone loaded with nitrogen doped carbon nanotubes (N-CNTs) were prepared by sol-gel method and deposited on Indium Tin Oxide (ITO) glass substrates at room temperature. Further examination of optical properties aimed the investigation of optical pseudo-gap and Urbach energy and enabled the determination of processed films thickness based on Manifacier and Swanepol method. The results indicated that the unloaded thin films have a direct optical transition with a value of 3.61 eV followed by noticeable shift towards narrowing gaps depending on the loading rate. Urbach's energy is 0.19 eV for the unloaded thin films, and varies from 0.43 to 1.33 eV for the loaded thin films with increasing the rate of N-CNTs. It is inversely variable with the optical pseudo-gap. Finally, Epoxy/Silicone loaded with N-CNTs nanocomposites films can be developed as active layers with specific optical characteristics, giving the possibility to be used in electro-optical applications.


2005 ◽  
Vol 871 ◽  
Author(s):  
Z. T. Liu ◽  
C. C. Oey ◽  
A. B. Djuriši ◽  
C. Y. Kwong ◽  
C. H. Cheung ◽  
...  

AbstractIn this work, optical functions of some widely used OLEDs materials 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), tris (8-hydroxyquinoline) aluminum (Alq3), (N,N′-di(naphthalene-1-yl)-N,N′- diphenylbenzidine (NPB),poly(3,4,-ethylene dioxythiophene):polystyrene sulfonic acid (PEDOT:PSS) and indium tin oxide (ITO)) were studied using spectroscopic ellipsometry (SE) in the spectral range from 1.55 eV to 4.1 eV (wavelength range of 300 nm to 800 nm). The samples were prepared either by thermal evaporation in high vacuum or spin-coating of thin films onto glass substrates. For determination of the optical functions of ITO, commercial ITO glass was used. Measurements at different incident angles were performed to determine whether the samples can be considered isotropic. The SE data were modeled using an oscillator model (Lorentz for semiconducting and Lorentz-Drude for conducting materials). The absorption spectra were also measured, and the comparison with the data determined by SE is given.


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