Fluorine Doping Effects on the Electric Property of BiFeO3 Thin Films

2014 ◽  
Vol 624 ◽  
pp. 161-164
Author(s):  
Fang Long Xu ◽  
Peng Jun Zhao ◽  
Jia Qi Zhang ◽  
Xin Qian Xiong

F doping BiFeO3-xFx (x=0, 0.02, 0.04, 0.06, 0.08) thin films were successfully fabricated on ITO/glass substrates by sol-gel method. X-ray diffraction analysis indicated that the un-doped BiFeO3 and F doping BiFeO3 thin films presented rhombohedral structure with the space group R3c. F-doping is found to significantly enhance the dielectric constant and decrease the leakage current density for x=0.08 compared with x=0. This study provides direct evidence that the multiferroic characteristics of BiFeO3 are sensitive to the anion doping, such as F, providing a convenient alternative to manipulate the electric polarization in multiferroic oxides.

2008 ◽  
Vol 15 (01n02) ◽  
pp. 13-18
Author(s):  
X. T. LI ◽  
C. WU ◽  
W. J. WENG ◽  
G. R. HAN ◽  
P. Y. DU

A series of ( Pb 0.4 Sr 0.6)1-x La 2x/3 TiO 3 (PSLT) thin films were deposited on ITO/glass substrates by sol–gel technique. Their phase status, surface morphology, and dielectric properties were studied by X-ray diffraction, scanning electron microscope, and impedance analyzer, respectively. Results show that the PSLT thin films were consisted of tetragonal perovskite phase PSLT thin films for x < 0.4, and cubic perovskite phase PSLT thin films for x > 0.4. Dielectric properties such as dielectric constants, dielectric tunabilitis, and inharmonic coefficient were characterized as a function of the film composition.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Younes Ziat ◽  
Hamza Belkhanchi ◽  
Maryama Hammi ◽  
Ousama Ifguis

Thin films of epoxy/silicone loaded with N-CNT were prepared by a method of sol-gel and deposited on ITO glass substrates at room temperature. The properties of the loaded monolayer samples (0.00, 0.07, 0.1, and 0.2 wt% N-CNTs) were analyzed by UV-visible spectroscopy. The transmittance for the unloaded thin films is 88%, and an average transmittance for the loaded thin film is about 42 to 67% in the visible range. The optical properties were studied from UV-visible spectroscopy to examine the transmission spectrum, optical gap, Tauc verified optical gap, and Urbach energy, based on the envelope method proposed by Swanepoel (1983). The results indicate that the adjusted optical gap of the film has a direct optical transition with an optical gap of 3.61 eV for unloaded thin films and 3.55 to 3.19 eV for loaded thin films depending on the loading rate. The optical gap is appropriately adapted to the direct transition model proposed by Tauc et al. (1966); its value was 3.6 eV for unloaded thin films and from 3.38 to 3.1 eV for loaded thin films; then, we determined the Urbach energy which is inversely variable with the optical gap, where 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 rate of N-CNTs. Finally, nanocomposite epoxy/silicone N-CNT films can be developed as electrically conductive materials with specific optical characteristics, giving the possibility to be used in electrooptical applications.


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.


2001 ◽  
Vol 15 (17n19) ◽  
pp. 769-773 ◽  
Author(s):  
M. GARCIA-ROCHA ◽  
A. CONDE-GALLARDO ◽  
I. HERNANDEZ-CALDERON ◽  
R. PALOMINO-MERINO

In this work we show the results on tile growth and optical characterization of TiO 2 thin films doped with Eu atoms. Eu:TiO2 films were grown at room temperature with different Eu concentrations by sol-gel on Si Corning glass substrates. A different crystalline structure is developed for the films deposited on Corning glass than those deposited on Si as observed from x-ray diffraction experiments. Room and low temperature photoluminescence (PL) was measured by using two different lines (325 and 442 nm) of a HeCd laser. A strong PL signal associated to the 5 D 0→7 F 2 transition from Eu +3 was observed. A better emission was obtained from those films deposited on Si substrates, Finally, the evolution of the PL signal is studied when the samples are annealed at different temperatures in O 2 atmosphere.


2013 ◽  
Vol 690-693 ◽  
pp. 1659-1663
Author(s):  
Hai Fang Zhou ◽  
Xiao Hu Chen

The preparation and characterization of CuInS2 thin films on ITO glass substrates prepared by one-step electrodeposition have been reported. Samples were characterized using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The results indicate that CuInS2 is the major phase for the film deposited at -1.0 V, after annealing at 550°C in sulfur atmosphere, and the sample is Cu-rich and p-type semiconductor. Additionally, the energy band gap and carrier concentration for the sample were found to be 1.43 eV and 4.20×1017 cm−3, respectively. Furthermore, the maximum photocurrent density of the sample was found to be -1.15 mA/cm2 under 255 lx illumination, the sample shows the photo-enhancement effect.


2013 ◽  
Vol 16 (1) ◽  
pp. 92-100
Author(s):  
Chien Mau Dang ◽  
Dam Duy Le ◽  
Tam Thi Thanh Nguyen ◽  
Dung Thi My Dang

In this study, we have successfully synthesized Fe3+ doped SiO2/TiO2 thin films on glass substrates using the sol-gel dip-coating method. After synthesizing, the samples were annealed at 5000C in the air for 1 hour. The characteristics and optical properties of Fe3+ doped SiO2/TiO2 films were then investigated by X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FT-IR). An antifogging ability of the glass substrates coated with the fabricated film is investigated and explained by a water contact angle under visible-light. The analyzed results also show that the crystalline phase of TiO2 thin films comprised only the anatase TiO2, but the crystalline size decreased from 8.8 to 5.9 nm. We also observed that the absorption edge of Fe3+- doped SiO2/TiO2 thin films shifted towards longer wavelengths (i.e. red shifted) from 371.7nm to 409.2 nm when the Fe3+-doped concentration increased from 0 to 1 % mol.


2012 ◽  
Vol 485 ◽  
pp. 144-148
Author(s):  
Jian Lin Chen ◽  
Yan Jie Ren ◽  
Jian Chen ◽  
Jian Jun He ◽  
Ding Chen

Preferentially oriented Al-doped ZnO thin films with doping concentration of 1, 2, 3, 5 and 10 mol% respectively were prepared on glass substrates via sol-gel route. The crystallinity of films was characterized by X-ray diffraction and the surface morphologies were observed by scanning electron microscopy. The results show that ZnO:Al films at low doping concentration (1, 2 mol%) grow into dense homogenous microstructure. However, as for high doping concentration (3, 5, 10 mol%), Al3+ precipitate in the form of amorphous Al2O3 and ZnO:Al films exhibit heterogeneous nucleation and exceptional growth of the big plate-like crystals at the interface of the amorphous Al2O3 and ZnO:Al matrix.


Author(s):  
CHIEN-MIN CHENG ◽  
MING-CHANG KUAN ◽  
KAI-HUNAG CHEN ◽  
JEN-HWAN TSAI

In this study, ferroelectric CaBi 4 Ti 4 O 15 (CBT) thin films prepared by sol-gel method and deposited on ITO/glass substrates for applications in system-on-panel (SOP) devices were fabricated and investigated. The electrical and physical characteristics of as-deposited and annealed CBT thin films for metal-ferroelectric-metal (MFM) structures was discussed and investigated. In addition, the ferroelectric properties in annealed CBT thin films on ITO/glass substrate showed and exhibited clear polarization versus electrical field curves. From p - E curves, the 2 P r value and coercive field of annealed CBT thin films were calculated to be 10μC/cm2 and 180 kV/cm, respectively. Finally, the maximum capacitance, leakage current density, and transmittance within the ultraviolet-visible (UV–vis) spectrum were also investigated and discussed.


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.


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