Quantitative investigation of polarization-dependent photocurrent in ferroelectric thin films

2021 ◽  
Author(s):  
Komalika Rani ◽  
Sylvia Matzen ◽  
Stéphane Gable ◽  
Thomas Maroutian ◽  
Guillaume Agnus ◽  
...  
Keyword(s):  
Thin Films ◽  
Photovoltaic Effect ◽  
Quantitative Relationship ◽  
Open Circuit ◽  
Ferroelectric Thin Films ◽  
Ferroelectric Polarization ◽  
Ferroelectric Layer ◽  
Ferroelectric Memories ◽  
Careful Investigation

Abstract Ferroelectric thin films are investigated for their potential in photovoltaic (PV) applications, owing to their high open-circuit voltage and switchable photovoltaic effect. The direction of the ferroelectric polarization can control the sign of the photocurrent through the ferroelectric layer, theoretically allowing for 100 percent switchability of the photocurrent with the polarization, which is particularly interesting for photo-ferroelectric memories. However, the quantitative relationship between photocurrent and polarization remains little studied. In this work, a careful investigation of the polarization-dependent photocurrent of epitaxial Pb(Zr,Ti)O3 thin films has been carried out, and has provided a quantitative determination of the unswitchable part of ferroelectric polarization. These results represent a systematic approach to study and optimize the switchability of photocurrent, and more broadly to get important insights on the ferroelectric behavior in all types of ferroelectric layers in which pinned polarization is difficult to investigate.

Photovoltaic effect in rhombohedral and tetragonal phase BiFeO3 ferroelectric thin films

2018 ◽  
Vol 192 (1) ◽  
pp. 146-153
Author(s):  
Rongli Gao ◽  
Chunlin Fu ◽  
Wei Cai ◽  
Gang Chen ◽  
Xiaoling Deng ◽  
...  
Keyword(s):  
Thin Films ◽  
Tetragonal Phase ◽  
Photovoltaic Effect ◽  
Ferroelectric Thin Films

Quantitative XPS determination of Pt coverage on SrBi2Ta2O9 thin films for ferroelectric memories

2001 ◽  
Vol 31 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Katsuhiko Asami ◽  
Ichiro Koiwa ◽  
Tomomi Yamanobe
Keyword(s):  
Thin Films ◽  
Ferroelectric Memories

Enhanced photovoltaic effect in Bi2FeMo0.7Ni0.3O6 ferroelectric thin films by tuning the thickness

2020 ◽  
Vol 8 (4) ◽  
pp. 1359-1365 ◽  
Author(s):  
Xiaxia Cui ◽  
Yong Li ◽  
Xiaowei Li ◽  
Xihong Hao
Keyword(s):  
Thin Films ◽  
Driving Force ◽  
Photovoltaic Effect ◽  
Photovoltaic Performance ◽  
Ferroelectric Thin Films

An enhanced photovoltaic performance is achieved by self-polarization of Bi2FeMo0.7Ni0.3O3 ferroelectric thin films by tuning the driving force based on the change of thickness.

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.

Evaluation of Ferroelectricity in MFIS Type Capacitor Using Pulsed C-V Measurements

1999 ◽  
Vol 596 ◽  
Author(s):  
Norifumi Fujimura ◽  
Takeshi Yoshimura ◽  
Taichiro Ito
Keyword(s):  
Thin Films ◽  
Space Charge ◽  
Leakage Current ◽  
Remanent Polarization ◽  
Interfacial Polarization ◽  
Ferroelectric Thin Films ◽  
Real Component ◽  
Simple Method ◽  
Si Substrates ◽  
Ferroelectric Layer

AbstractWe have been proposing YMnO3 with low remanent polarization and dielectric permittivity as a transistor type FeRAM. Conventional C-V measurements are normally used to evaluate the ferroelectricity of ferroelectric thin films on Si substrates. For ferroelectric thin films with low polarization, however, there are some issues to understand the C-V hysteresis. For example, interfacial polarization and space charge affect the C-V hysteresis. The effect of interfacial polarization on C-V behavior was calculated assuming the connection of ferroelectric and dielectric layers with different resistivity. If a ferroelectric layer with a leakage current of 1×10-6 A/cm2 is connected to the dielectric layer with a leakage current of 1×10-9 A/cm2, a charge density of 10-9 C/cm2 should be generated in the period of 0.2 sec. Space charge should have a longer time constant for accumulating the charge. Pulsed C-V measurement must be effective to avoid these issues. This paper proposes a simple method to evaluate the real component of ferroelectricity in the C-V hysteresis using YMnO3 or ZnO:Li with very low remanent polarization.

Microstructure Characterization of Ferroelectric Thin Films used in Non-Volatile Memories - Optical and Scanning Electron Microscopy

1990 ◽  
Vol 200 ◽  
Author(s):  
Leo N. Chapin ◽  
Sharon A. Myers
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Ferroelectric Thin Films ◽  
Fully Integrated ◽  
Ferroelectric Layer ◽  
Scanning Electron

ABSTRACTLead zirconate titanate ferroelectric thin films have been fabricated and fully integrated with standard CMOS semiconductor technology to produce non-volatile IC memory devices, now being tested in the marketplace. Starting with an organo-metallic sol-gel and using standard IC spin-on glass and annealing technologies, perovskite type ferroelectric thin films are formed. A variety of techniques have been under study for characterizing the crystalline microstructumre of the ferroelectric layer. Presented here are observations made with optical and scanning electron microscopy, and X-ray diffraction analysis of the effects of ferroelectric composition and sinter temperatures on crystal structure.

Chemical Vapor Deposition of Electroceramic Thin Films

MRS Bulletin ◽  
1996 ◽  
Vol 21 (6) ◽  
pp. 37-43 ◽  
Author(s):  
M. de Keijser ◽  
G.J.M. Dormans
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Low Voltage ◽  
Thin Film Deposition ◽  
Ferroelectric Material ◽  
Film Deposition ◽  
Ferroelectric Capacitor ◽  
Nonvolatile Memories ◽  
Ferroelectric Layer ◽  
Ferroelectric Memories

A nonconventional way of producing nonvolatile memories is to use ferroelectrics, a class of electroceramic materials. These materials have a remanent polarization. The direction of this polarization can be changed by an electric field. Ferroelectric materials possess a “natural memory,” so to speak. Ferroelectrics have been known for a long time, and the idea to use them for binary data storage originates in the 1950s. The basic element of this type of memory is formed by a ferroelectric capacitor—a ferroelectric layer sandwiched between electrodes. Early prototypes were unsuccessful because rather high voltages were needed to switch the ferroelectric capacitor (200–300 V) and the memories suffered from crosstalk. (Programming one particular cell influenced neighboring cells.) The revival of ferroelectric memories was driven by the development of thin-film deposition techniques that allowed the formation of capacitors with ferroelectric thin films of submicron thicknesses. These capacitors can be switched with normal intergrated-circuit (IC) voltages. The crosstalk problem is circumvented by isolating each memory cell by a transistor (similar to a dynamic random-access memory [DRAM]). Compared to “standard” nonvolatile memories, ferroelectric memories offer the advantage of very fast access times (both for reading and writing), low-voltage operation, and good write/read endurance. A ferroelectric material that is already being used in commercially available memories is lead zirconate titanate, PbZrxTi 1−xO3. To combine a ferroelectric material with IC technology is a challenge, and many problems have been (and will be) encountered.

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.

Nanoscale Scanning Force Imaging of Polarization Phenomena in Ferroelectric Thin Films

MRS Bulletin ◽  
1998 ◽  
Vol 23 (1) ◽  
pp. 33-42 ◽  
Author(s):  
O. Auciello ◽  
A. Gruverman ◽  
H. Tokumoto ◽  
S.A. Prakash ◽  
S. Aggarwal ◽  
...  
Keyword(s):  
Thin Films ◽  
High Speed ◽  
Science And Technology ◽  
Hysteresis Loops ◽  
Ferroelectric Thin Film ◽  
Ferroelectric Thin Films ◽  
Exact Nature ◽  
Electrical Measurements ◽  
Ferroelectric Layer ◽  
Polarization Phenomena

The science and technology of ferroelectric thin films is currently attracting worldwide attention because of its application to a new generation of novel devices. Prime, among these applications are nonvolatile ferroelectric random-access memories (NVFRAMs), which have high speed and extended endurance. The core of an NVFRAM is a capacitor with a ferroelectric film sandwiched between two electrode layers. The polarization of the ferroelectric layer in two possible opposite directions, upon application of an electric field between the two electrodes, provides the logic “1” and “0” states needed for binary-code memory. In spite of the advances in the science and technology of ferroelectric thin films and their integration into ferroelectric capacitors, some materials-related integration strategies as well as manufacturability issues have delayed commercialization of NVFRAMs. High-density memories require storage elements that approach submicron lateral dimensions. Thus, improved understanding of the materials properties and polarization phenomena is needed in conjunction with the development of new characterization tools that can enable such an understanding. For example, a fundamental issue in ferroelectric thin-film capacitors is the exact nature of the complex domain structure in the polarizable ferroelectric layer and its dynamics under high-speed switching conditions. The miniaturization of NVFRAMs requires understanding of granularity in polarization reversal dynamics, fatigue, and retention characteristics. In this respect, theoretical models and electrical measurements (e.g., polarization hysteresis loops and transient currents) have provided substantial insights into the nature of the switching processes. However, the models (phenomenological in nature) and the electrical measurements provide only a global or macroscopic view of the switching process.

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