scholarly journals Сравнение характеристик тонких пленок PZT на подложках из сапфира и кремния

2021 ◽  
Vol 63 (8) ◽  
pp. 1076
Author(s):  
Л.А. Делимова ◽  
Н.В. Зайцева ◽  
В.В. Ратников ◽  
В.С. Юферев ◽  
Д.С. Серегин ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
Lattice Mismatch ◽  
Short Circuit ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Film Plane ◽  
Open Circuit ◽  
Transient Current ◽  
Si Substrate ◽  
Pzt Films

The properties of ferroelectric sol-gel PZT films deposited on a silicon-on-sapphire (SOS) substrate are compared with those of PZT films formed on a Si substrate. The crystalline structure, asymmetry of the hysteresis loops, polarization dependences of the transient current, short-circuit photocurrent, and open-circuit photovoltage, as well as the substrate bending have been studied. The PZT on SOS films are textured in a single (111) direction and exhibit symmetric hysteresis loops with a strong remanent polarization. The PZT films on Si are textured in the main (111) and weaker (100) directions, have weaker polarization, and exhibit an asymmetry of the hysteresis loops, which is reflected in the magnitude of the transient current and photocurrent. It is shown that the sapphire substrate has a convex bending that causes a compressive stress in the film plane, which weakens the effect of the lattice mismatch between PZT and Pt. By contrast, the Si substrate has a concave curvature, which causes the film to stretch. The deformations and mechanical stresses within the films were estimated. For PZT on Si, an estimate of the strain gradient along the (111) axis was obtained, which makes it possible to relate the asymmetry of the hysteresis loops to the flexoelectric polarization, with the flexoelectric coefficient for sol-gel PZT films found to be 0.0154 µC/cm. The results obtained show that the sapphire substrate provides a better quality of thin PZT films.

Giant Self-Polarization in FeRAM Element Based on Sol-Gel PZT Films

2015 ◽  
Vol 1729 ◽  
pp. 87-92
Author(s):  
L. A. Delimova ◽  
E. V. Guschina ◽  
V. S. Yuferev ◽  
I. V. Grekhov ◽  
N. V. Zaiceva ◽  
...  
Keyword(s):  
Bottom Electrode ◽  
Lattice Mismatch ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Polarization Switching ◽  
Driving Voltage ◽  
Lattice Constants ◽  
Modified Method ◽  
Pzt Film ◽  
Pzt Films

ABSTRACTIntegrated ferroelectric capacitors Pt/PZT/Pt/Ti/SiO2/Si with sol-gel deposited PZT films are studied. The (111) textured polycrystalline films are shown to have nonconductive PZT grain boundaries. The short-circuited photocurrents measured under illumination of the films by light with the quantum energy of 2.7 eV indicate the polarization inside the film directed from the top to the bottom electrode. Using the modified method of depolarization hysteresis loops, we found a non-switchable part of polarization which was measured to be -16 μC/cm2 and directed from the top to the bottom electrode. We consider this result to be a giant self-polarization and explain it in terms of flexoelectricity caused by lattice mismatch between the PZT and bottom Pt layers. The strain gradient across the PZT film thickness is estimated from the in-plane lattice constants measured in Pt and PZT films to be ∼103cm-1, which can produce the downward flexoelectric polarization of ∼14 μC/cm2, coinciding well with the measured one. Nonsymmetrical depolarization loops are found in the films when the polarization switching itself becomes more difficult under the negative or positive driving voltage. We show experimentally how depolarization with compensating bias or film illumination can affect the film polarization switching.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

Preparation of Cu2ZnSnS4 Treated with Post-Sulfurization in a Sulfur Vapor Atmosphere

2011 ◽  
Vol 239-242 ◽  
pp. 642-645 ◽  
Author(s):  
Min Yen Yeh ◽  
Dong Sing Wuu
Keyword(s):  
Spin Coating ◽  
Electrical Resistance ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Sulfur Vapor ◽  
Crystallinity Degree ◽  
Composition Ratios

Cu2ZnSnS4 (CZTS) prepared by sol-gel spin-coating deposition was treated with post-sulfurization in a sulfur vapor atmosphere. The crystallinity degree of the CZTS could be significantly improved through post-sulfurization treatment. Granular structures of the CZTS as synthesized at a temperature of over 240 °C and treated with post sulfurization were obtained. The composition ratios of the as-sulfurized CZTS were close to the composition stoichiometry of CZTS with an electrical resistance of ~ 1.7 Ω cm. An as-prepared CZTS based solar cell shows an open-circuit voltage of 300 mV, and a short-circuit current of 2.48 mA cm-2.

scholarly journals Facile NiOx Sol-Gel Synthesis Depending on Chain Length of Various Solvents without Catalyst for Efficient Hole Charge Transfer in Perovskite Solar Cells

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1227 ◽  
Author(s):  
Byung Kim ◽  
Woongsik Jang ◽  
Dong Wang
Keyword(s):  
Solar Cells ◽  
Chain Length ◽  
Short Circuit ◽  
Sol Gel ◽  
Perovskite Solar Cells ◽  
Open Circuit ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Perovskite Layer

Nickel oxide (NiOx)–based perovskite solar cells (PSCs) have recently gained considerable interest, and exhibit above 20% photovoltaic efficiency. However, the reported syntheses of NiOx sol-gel used toxic chemicals for the catalysts during synthesis, which resulted in a high-temperature annealing requirement to remove the organic catalysts (ligands). Herein, we report a facile “NiOx sol-gel depending on the chain length of various solvents” method that eschews toxic catalysts, to confirm the effect of different types of organic solvents on NiOx synthesis. The optimized conditions of the method resulted in better morphology and an increase in the crystallinity of the perovskite layer. Furthermore, the use of the optimized organic solvent improved the absorbance of the photoactive layer in the PSC device. To compare the electrical properties, a PSC was prepared with a p-i-n structure, and the optimized divalent alcohol-based NiOx as the hole transport layer. This improved the charge transport compared with that for the typical 1,2-ethanediol (ethylene glycol) used in earlier studies. Finally, the optimized solvent-based NiOx enhanced device performance by increasing the short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF), compared with those of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)–based devices.

Fabrication and I-V Characteristics of Nanocrystalline Titania Electrode Sensitized by Zinc Phthalocyanine

2006 ◽  
Vol 326-328 ◽  
pp. 365-368 ◽  
Author(s):  
Yu Qiao Wang ◽  
Chun Ping Liu ◽  
Kang Li ◽  
Yue Ming Sun
Keyword(s):  
Lauric Acid ◽  
Short Circuit ◽  
Transparent Conducting Oxide ◽  
Sol Gel ◽  
Photocurrent Density ◽  
Open Circuit ◽  
Zinc Phthalocyanine ◽  
Solar Simulator ◽  
Oxide Substrate ◽  
Open Circuit Photovoltage

TiO2 colloids prepared by sol-gel method were autoclaved and then deposited onto a transparent conducting oxide substrate by screen-printing. The TiO2 films electrode was characterized by XRD, SEM, AFM and Alpha-Step profilometer and then sensitized by zinc phthalocyanine (ZnPc), 2,9,16,23-tetracarboxy zinc phthalocyanine (ZnTCPc) and ZnTCPc/lauric acid respectively. Photocurrent density (I) and photovoltage (V) of the electrode were measured with the solar simulator. The ZnTCPc-sensitized electrode was found the best performance with the short-circuit photocurrent density (Isc) 16.66 3A/cm2, the open-circuit photovoltage (Voc) 277.9 mV and the fill factor (FF) 0.39. And the ZnPc-sensitized electrode was found the worst performance with Voc 114.2 mV, Isc 2.26 3A/cm2 and FF 0.31. It was also found that lauric acid promoted Voc of the the ZnTCPc sensitized system.

EFFECT OF PRE-HEATING TEMPERATURE ON THE CHARACTERISTICS OF PZT THIN FILMS GROWN BY USING A TRIOL SOL–GEL ROUTE

2007 ◽  
Vol 14 (02) ◽  
pp. 229-234
Author(s):  
SARAWUT THOUNTOM ◽  
MANOCH NAKSATA ◽  
KENNETH MACKENZIE ◽  
TAWEE TUNKASIRI
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Heating Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Lead Zirconate ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
Ferroelectric Hysteresis

Lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were fabricated on Pt (111)/ Ti / SiO 2/ Si (100) using the triol sol–gel method. The effect of the pre-heating temperature on the phase transformations, microstructures, electrical properties, and ferroelectric properties of the PZT thin films was investigated. Randomly oriented PZT thin films pre-heated at 400°C for 10 min and annealed at 600°C for 30 min showed well-defined ferroelectric hysteresis loops with a remnant polarization of 26.57 μC/cm2 and a coercive field of 115.42 kV/cm. The dielectric constant and dielectric loss of the PZT films were 621 and 0.0395, respectively. The microstructures of the thin films are dense, crack-free, and homogeneous with fine grains about 15–20 nm in size.

Photovoltaic Effects of Bismuth Ferrite and Nd-Doped Barium Titanate Thin Films Prepared by Sol-Gel Method

2014 ◽  
Vol 787 ◽  
pp. 347-351 ◽  
Author(s):  
Chun Lin Fu ◽  
Wei Cai ◽  
Ze Bin Lin ◽  
Wei Hai Jiang
Keyword(s):  
Thin Films ◽  
Barium Titanate ◽  
Short Circuit ◽  
Bismuth Ferrite ◽  
Power Conversion ◽  
Sol Gel ◽  
Photocurrent Density ◽  
Open Circuit ◽  
Doped Barium Titanate ◽  
Open Circuit Photovoltage

Ferroelectric is a great potential material as new solar cells, light driver and optical sensor because of its anomalous photovoltaic effect. Bismuth ferrite and Nd-doped barium titanate thin films were prepared via sol–gel spin-coating method in the present study. The experimental results show that substitution of Nd3+ ions for Ba2+ on A sites leads to the decrease of band gap, and the short circuit photocurrent density, open circuit photovoltage and power conversion efficiency of Nd-doped barium titanate thin films begin to increase and reach the maximum and then decrease as Nd content increases. It has been found that the band gap of bismuth ferrite thin films annealed at 550–650oC was between 2.306 eV and 2.453 eV. The short circuit photocurrent density decreased with the rise of annealing temperature, and the open circuit photovoltage and the power conversion efficiency of bismuth ferrite thin films annealed at 550oC were higher than the thin films annealed at higher temperature.

scholarly journals Fabrication of Hybrid Polymer Solar Cells By Inverted Structure Based on P3HT:PCBM Active Layer

2017 ◽  
Vol 17 (1) ◽  
pp. 13
Author(s):  
Shobih Shobih ◽  
Rizky Abdillah ◽  
Erlyta Septa Rosa
Keyword(s):  
Solar Cells ◽  
Active Layer ◽  
Bulk Heterojunction ◽  
Polymer Solar Cells ◽  
Short Circuit ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Hybrid Polymer

Hybrid polymer solar cell has privilege than its conventional structure, where it usually has structure of (ITO/PEDOT:PSS/Active Layer/Al). In humid environment the PEDOT:PSS will absorb water and hence can easily etch the ITO. Therefore it is necessary to use an alternative method to avoid this drawback and obtain more stable polymer solar cells, namely by using hybrid polymer solar cells structure with an inverted device architecture from the conventional, by reversing the nature of charge collection. In this paper we report the results of the fabrication of inverted bulk heterojunction polymer solar cells based on P3HT:PCBM as active layer, utilizing ZnO interlayer as buffer layer between the ITO and active layer with a stacked structure of ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag. The ZnO interlayer is formed through short route, i.e. by dissolving ZnO nanoparticles powder in chloroform-methanol solvent blend rather than by sol-gel process. Based on the measurement results on electrical characteristics of inverted polymer solar cells under 500 W/m2 illumination and AM 1.5 direct filter at room temperature, cell with annealing process of active layer at 110 °C for 10 minutes results in higher cell performance than without annealing, with an open-circuit voltage of 0.21 volt, a short-circuit current density of 1.33 mA/cm2 , a fill factor of 43.1%, and a power conversion efficiency of 0.22%. The low cell’s performance is caused by very rough surface of ZnO interlayer.

scholarly journals Performance Analysis of Mixed Natural Dye and Nanostructured Tio2 based DSSC

2020 ◽  
Vol 9 (7) ◽  
pp. 453-456
Keyword(s):  
Short Circuit ◽  
Electron Flow ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Natural Dye ◽  
Nanostructured Tio2 ◽  
Beet Root ◽  
The Stability ◽  
The Individual

The performance of the mixed natural dye based DSSC has been evaluated in this paper. The mixture of beet root, spinach and turmeric are used with nanostructured TiO2 are used for the fabrication of DSSC. TiO2 is synthesized by sol-gel technique and considered as semiconductor metal oxide (SMO) to act as photo anode here. Nano wire type of morphology of TiO2 is found from the FESEM image which exhibits unidirectional and uniform electron flow. The XRD study reveals anatase and rutile phases of TiO2 that ensure the stability of synthesized TiO2 . The mixed dye made of beet root, spinach and turmeric shows their congruent characteristics with the broad light absorption spectra, lower diffused reflectance spectra after anchoring with SMO and better I-V characteristics in comparison with the individual one. The mixed dye-based DSSC provides the open-circuit voltage of 0.755V, short circuit current of 2.05mA, voltage and current at maximum power equal to 0.51V and 1.7mA, respectively with the efficiency of 0.867 %, in comparison to the efficiency of the individual dyes 0.305%, 0.266% and 0.473% with beet root, spinach and turmeric, respectively.

scholarly journals A Study on the Effects of Selenization Temperature on the Properties of Na-Doped Cu2ZnSn(S,Se)4 Thin Film and Its Correlation with the Performance of Solar Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2434
Author(s):  
Zhanwu Wang ◽  
Dongyue Jiang ◽  
Fancong Zeng ◽  
Yingrui Sui
Keyword(s):  
Fill Factor ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Sol Gel ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Post Annealing ◽  
Different Temperatures ◽  
Selenization Temperature

In this study, we prepared Na-doped Cu2ZnSn(S,Se)4 [noted as (Na0.1Cu0.9)2ZnSn(S,Se)4] films on the Mo substrate using a simple and cheap sol–gel method together with the post-annealing technique. The effects of selenization temperature on the properties of Na-doped Cu2ZnSn(S,Se)4 were surveyed. The results indicated that some sulfur atoms in the films were substituted by selenium atoms by increasing the selenization temperature, and all films selenized at different temperatures had a kesterite structure. As the selenization temperature increased from 520 to 560 °C, the band gaps of the film can be tuned from 1.03 to 1 eV. The film with better morphology and opto-electrical properties can be obtained at an intermediate selenization temperature range (e.g., 540 °C), which had the lowest resistivity of 47.7 Ω cm, Hall mobility of 4.63 × 10−1 cm2/Vs, and carrier concentration of 2.93 × 1017 cm−3. Finally, the best power conversion efficiency (PCE) of 4.82% was achieved with an open circuit voltage (Voc) of 338 mV, a short circuit current density (Jsc) of 27.16 mA/cm2 and a fill factor (FF) of 52.59% when the selenization temperature was 540 °C.

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