Enhancement of Oxygen Vacancies Induced Photovoltaic Effects in Bi0.9La0.1FeO3 Thin Films

2015 ◽  
Vol 815 ◽  
pp. 176-182 ◽  
Author(s):  
Rong Li Gao ◽  
Chun Lin Fu ◽  
Wei Cai ◽  
Gang Chen ◽  
Xiao Ling Deng ◽  
...  
Keyword(s):  
Thin Films ◽  
Oxygen Vacancies ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
Ferroelectric Films ◽  
Electric Pulses ◽  
Photovoltaic Effects ◽  
Drift Current ◽  
Polarization Orientation ◽  
And Diffusion

The photovoltaic effect in Ag/Bi0.9La0.1FeO3/La0.7Sr0.3MnO3heterostructures was investigated and the short circuit photocurrent was found to be strongly dependent on the polarization orientation and oxygen vacancies (VOs) distribution. The photocurrent direction was switched accompanying polarization switching. Besides, according to manipulate theVOsaccumulated at either the Ag/Bi0.9La0.1FeO3or the Bi0.9La0.1FeO3/La0.7Sr0.3MnO3interface by electric pulses, obvious enhancement of photovoltaic effects was obtained. These results can be explained well using the concepts of drift current and diffusion current controlled by the combination of oxygen vacancies and polarization. This work provides deep insights into the nature of photovoltaic effects in ferroelectric films, and will facilitate the advanced design devices combining spintronic, electronic, and optical functionalities.

Electrical Characterization of Ferroelectric Thin Films of Lithium Niobate on Silicon Substrates

1990 ◽  
Vol 200 ◽  
Author(s):  
Robert C. Baumann ◽  
Timothy A. Rost ◽  
Thomas A. Rabson
Keyword(s):  
Thin Films ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
Electrical Characterization ◽  
Oxide Semiconductor ◽  
Silicon Substrates ◽  
Small Areas ◽  
Transient And Steady State ◽  
Ferroelectric Switching

ABSTRACTThin films (.1-.6 μm) of LiNbO3 have been deposited on silicon substrates by rf reactive sputtering. MFS (metal-ferroelectric-semiconductor) capacitor structures were created by a liftoff process which physically isolated small areas of LiNbO3. Standard MOS (metal-oxide-semiconductor) electrical characterization techniques were used to determine the resistivity and dielectric constant of the films. Short-circuit photocurrent measurements revealed both transient and steady state components attributed to a pyroelectric effect and a bulk photovoltaic effect respectively. The conduction processes in these films were examined and found to exhibit Frenkel-Poole characteristics. Ferroelectric switching at room temperature has also been observed in these films, however, the reversed orientation was not stable.

scholarly journals Domain and Switching Control of the Bulk Photovoltaic Effect in Epitaxial BiFeO3 Thin Films

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
David S. Knoche ◽  
Yeseul Yun ◽  
Niranjan Ramakrishnegowda ◽  
Lutz Mühlenbein ◽  
Xinye Li ◽  
...  
Keyword(s):  
Electric Fields ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Inversion Symmetry ◽  
Bifeo3 Thin Films ◽  
Piezoelectric Effects ◽  
Angular Dependency ◽  
Polarization Orientation ◽  
Domain Arrangement

Abstract Absence of inversion symmetry is the underlying origin of ferroelectricity, piezoelectricity, and the bulk photovoltaic (BPV) effect, as a result of which they are inextricably linked. However, till now, only the piezoelectric effects (inverse) have been commonly utilized for probing ferroelectric characteristics such as domain arrangements and resultant polarization orientation. The bulk photovoltaic effect, despite sharing same relation with the symmetry as piezoelectricity, has been mostly perceived as an outcome of ferroelectricity and not as a possible analytical method. In this work, we investigate the development of BPV characteristics, i.e. amplitude and angular dependency of short-circuit current, as the ferroelastic domain arrangement is varied by applying electric fields in planar devices of BiFeO3 films. A rather sensitive co-dependency was observed from measurements on sample with ordered and disordered domain arrangements. Analysis of the photovoltaic response manifested in a mathematical model to estimate the proportion of switched and un-switched regions. The results unravel the potential utility of BPV effect to trace the orientation of the polarization vectors (direction and amplitude) in areas much larger than that can be accommodated in probe-based techniques.

Photovoltaic Effect in Thin Ferroelectric Films

1991 ◽  
Vol 243 ◽  
Author(s):  
Philip S. Brody ◽  
B. J. Rod ◽  
L. P. Cook ◽  
P. K. Schenck
Keyword(s):  
Thin Films ◽  
Photovoltaic Effect ◽  
Ferroelectric Thin Films ◽  
Polarization Field ◽  
Polarization Reversal ◽  
Ferroelectric Films ◽  
Initial Current ◽  
Elapsed Time ◽  
Steady Current

AbstractPolarization-dependent photovoltaic currents are observed in continuously illuminated ferroelectric thin films under conditions of polarization reversal. Following reversal, an initial current rapidly decays to an essentially steady current, which then decays slowly with the current decreasing in proportion to the logarithm of elapsed time. These polarization-dependent currents are attributed to the action of internal fields on photocarriers where the fields result from the incomplete screening of the polarization field.

Photoelectric Characteristics of Rare Earth Element Er Doped Molybdenum Selenide Thin Films

2020 ◽  
Vol 15 (3) ◽  
pp. 384-388 ◽  
Author(s):  
Xiying Ma ◽  
Cheng Xu ◽  
Qiang Zhang ◽  
Weilin Shi
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Photoelectric Characteristics ◽  
Molybdenum Selenide

The preparation and the photoelectric characteristics of molybdenum selenide (MoSe2) films doped with the rare earth element Er3+ are presented herein. The surface mororphology, light absorption and emission of the undoped and Er3+ doped MoSe2 thin films were analyzed, we found that the Er3+ doped MoSe2 films exhibited more crystalline, and their mobility and conductivity were enhanced by about one order higher relative to that of the pure sample. Also, the optical absorptivity and luminous intensity of Er3+ doped MoSe2 were also enhanced by two times than that of the pure MoSe2. In addition, the photovoltaic effect of the Er3+-doped MoSe2 films increased significantly. The short-circuit current increased almost ten-fold, and the open-circuit voltage was enhanced four-fold. These results show that the Er3+ ions not only enhanced the conductivity, but also improved the optical properties of the films. The Er3+ doped MoSe2 may be applied to make sensitive light emitting devices and detectors.

scholarly journals Generating Electricity from Natural Evaporation Using PVDF Thin Films Incorporating Nanocomposite Materials

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 585
Author(s):  
Ariel Ma ◽  
Jian Yu ◽  
William Uspal
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Polyvinylidene Fluoride ◽  
Capillary Flow ◽  
Short Circuit ◽  
Current Source ◽  
Nanocomposite Materials ◽  
The Other ◽  
Pvdf Film ◽  
Ambient Conditions

Natural evaporation has recently come under consideration as a viable source of renewable energy. Demonstrations of the validity of the concept have been reported for devices incorporating carbon-based nanocomposite materials. In this study, we investigated the possibility of using polymer thin films to generate electricity from natural evaporation. We considered a polymeric system based on polyvinylidene fluoride (PVDF). Porous PVDF films were created by incorporating a variety of nanocomposite materials into the polymer structure through a simple mixing procedure. Three nanocomposite materials were considered: carbon nanotubes, graphene oxide, and silica. The evaporation-induced electricity generation was confirmed experimentally under various ambient conditions. Among the nanocomposite materials considered, mesoporous silica (SBA-15) was found to outperform the other two materials in terms of open-circuit voltage, and graphene oxide generated the highest short-circuit current. It was found that the nanocomposite material content in the PVDF film plays an important role: on the one hand, if particles are too few in number, the number of channels will be insufficient to support a strong capillary flow; on the other hand, an excessive number of particles will suppress the flow due to excessive water absorption underneath the surface. We show that the device can be modeled as a simple circuit powered by a current source with excellent agreement between the theoretical predictions and experimental data.

scholarly journals Photocurrent density and electrical properties of Bi0.5Na0.5TiO3-BaNi0.5Nb0.5O3 ceramics

2021 ◽  
Author(s):  
Mingqiang Zhong ◽  
Qin Feng ◽  
Changlai Yuan ◽  
Xiao Liu ◽  
Baohua Zhu ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Photocurrent Density ◽  
Open Circuit ◽  
Light Conditions ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray

AbstractIn this work, the (1−x)Bi0.5Na0.5TiO3-xBaNi0.5Nb0.5O3 (BNT-BNN; 0.00 ⩽ x ⩽ 0.20) ceramics were prepared via a high-temperature solid-state method. The crystalline structures, photovoltaic effect, and electrical properties of the ceramics were investigated. According to X-ray diffraction, the system shows a single perovskite structure. The samples show the normal ferroelectric loops. With the increase of BNN content, the remnant polarization (Pr) and coercive field (Ec) decrease gradually. The optical band gap of the samples narrows from 3.10 to 2.27 eV. The conductive species of grains and grain boundaries in the ceramics are ascribed to the double ionized oxygen vacancies. The open-circuit voltage (Voc) of ∼15.7 V and short-circuit current (Jsc) of ∼1450 nA/cm2 are obtained in the 0.95BNT-0.05BNN ceramic under 1 sun illumination (AM1.5G, 100 mW/cm2). A larger Voc of 23 V and a higher Jsc of 5500 nA/cm2 are achieved at the poling field of 60 kV/cm under the same light conditions. The study shows this system has great application prospects in the photovoltaic field.

scholarly journals Influence of Heterointerfaces on the Kinetics of Oxygen Surface Exchange on Epitaxial La1.85Sr0.15CuO4 Thin Films

2021 ◽  
Vol 11 (9) ◽  
pp. 3778
Author(s):  
Gene Yang ◽  
So-Yeun Kim ◽  
Changhee Sohn ◽  
Jong K. Keum ◽  
Dongkyu Lee
Keyword(s):  
Thin Films ◽  
Oxygen Vacancies ◽  
Elevated Temperatures ◽  
Surface Exchange ◽  
Electrical Conductivity Relaxation ◽  
Exchange Kinetics ◽  
Relaxation Curves ◽  
Kinetics Of ◽  
Oxygen Surface Exchange ◽  
Oxygen Surface

Considerable attention has been directed to understanding the influence of heterointerfaces between Ruddlesden–Popper (RP) phases and ABO3 perovskites on the kinetics of oxygen electrocatalysis at elevated temperatures. Here, we report the effect of heterointerfaces on the oxygen surface exchange kinetics by employing heteroepitaxial oxide thin films formed by decorating LaNiO3 (LNO) on La1.85Sr0.15CuO4 (LSCO) thin films. Regardless of LNO decoration, tensile in-plane strain on LSCO films does not change. The oxygen surface exchange coefficients (kchem) of LSCO films extracted from electrical conductivity relaxation curves significantly increase with partial decorations of LNO, whereas full LNO coverage leads to the reduction in the kchem of LSCO films. The activation energy for oxygen exchange in LSCO films significantly decreases with partial LNO decorations in contrast with the full coverage of LNO. Optical spectroscopy reveals the increased oxygen vacancies in the partially covered LSCO films relative to the undecorated LSCO film. We attribute the enhanced oxygen surface exchange kinetics of LSCO to the increased oxygen vacancies by creating the heterointerface between LSCO and LNO.

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