High‐Performance (Na0.5K0.5)NbO3 Thin Film Piezoelectric Energy Harvester

Kim, Bo Yun; Seo, In Tae; Lee, Youn Seon; Kim, Jin-Seong; Nahm, Sahn; Kang, Chong Yun; Yoon, Seok Jin; Paik, Jong Hoo; Jeong, Young Hun

doi:10.1111/jace.13238

Cited by 29 publications

(14 citation statements)

References 40 publications

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“…It is interesting to note that the d 33 value of the NKN film grown on the flexible TiN‐PI substrate (50 pm V −1 ) is larger than that of the NKN film grown on the rigid TiN‐Si substrate (25 pm V −1 ), as shown in Figure S9 (Supporting Information). This increased d 33 value may be explained by the removal of the constraint effect of the rigid TiN‐Si substrate, and a similar result was observed in the crystalline NKN film grown on the Pt‐Si substrate …”

Section: Nkn Piezoelectric Ngssupporting

confidence: 70%

Resistive Switching Memory Integrated with Nanogenerator for Self‐Powered Bioimplantable Devices

Kim

Lee

Hwang

et al. 2016

Adv Funct Materials

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Resistive random access memory (ReRAM) devices powered by piezoelectric nanogenerators (NGs) have been investigated for their application to future implantable biomedical devices. Biocompatible (Na0.5K0.5)NbO3 (NKN) films that are grown at 300 °C on TiN/SiO2/Si and flexible TiN/Polyimide (TiN‐PI) substrates are used for ReRAM and NGs, respectively. These NKN films have an amorphous phase containing NKN nanocrystals with a size of 5.0 nm. NKN ReRAM devices exhibit typical bipolar switching behavior that can be explained by the formation and rupture of oxygen‐vacancy filaments. They have good ReRAM properties such as a large ratio of RHRS to RLRS as well as high reliability. The NKN film grown on flexible TiN‐PI substrate exhibits a high piezoelectric strain constant of 50 pm V−1. The NKN NG has a large open‐circuit output voltage of 2.0 V and a short‐circuit output current of 40 nA, which are sufficient to drive NKN ReRAM devices. Stable switching properties with a large ON/OFF ratio of 102 are obtained from NKN ReRAM driven by NKN NG.

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Section: Nkn Piezoelectric Ngssupporting

confidence: 70%

Resistive Switching Memory Integrated with Nanogenerator for Self‐Powered Bioimplantable Devices

Kim

Lee

Hwang

et al. 2016

Adv Funct Materials

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Section: Challenges and Perspectivesmentioning

confidence: 99%

Evolution from Lead‐Based to Lead‐Free Piezoelectrics: Engineering of Lattices, Domains, Boundaries, and Defects Leading to Giant Response

Waqar

Chen

et al. 2021

Advanced Materials

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for piezoelectric devices was estimated to be worth $25.1 billion with a projected compounded annual growth rate (CAGR) of 6.2%. [6] However, the development of piezoelectrics took more than a century to evolve from quartz, which is among the first known piezoelectric materials, [7,8] to their current forms in the modern era. The evolution of piezoelectrics is, hence, rich with the exciting discoveries in fundamental physics, paving the way to the development of applications that changed the course of history. One such example is the invention of sonar by Paul Langevin and team in 1917 [9] which is still essentially implemented today for underwater acoustics and navigation. Later, the discovery of ferroelectricity in BaTiO 3 polycrystal in 1946 [10,11] and phase transition (now referred to as a morphotropic phase boundary (MPB)) in PbZrO 3 -PbTiO 3 solid solution in 1954 [12] stimulated a worldwide interest in gaining fundamental understanding of electromechanical coupling in ferroelectric materials to develop better and more reliable piezoelectric devices. [13][14][15] By contrast, the research on piezoelectrics in the past two decades has been driven mainly by the environmental and health concerns related to the toxicity of lead, which is a primary constituent of the widely used lead-based piezoelectric ceramics, [16,17] where the best known example is lead zirconium titanates (PZT). Consequently, the stringent regulations all over the world to restrict the use of lead [18] have resulted in the rise of "lead-free" ceramics which further gained popularity after Saito et al.'s discovery of large piezoelectric response in a lead-free piezoceramic. [19] These eco-friendly materials represent now although a relatively small part of the current piezoelectrics market, with a total estimate of around $172 million, but, their sales are projected to reach $443 million by 2024 with a CAGR of 20.8%. [6] ABO 3 -type perovskite oxide ferroelectrics hold great technical value owing to their large spontaneous polarization, which makes them highly suitable for piezoelectric applications. [1,3,20] In recent years, the research efforts have been primarily focused on developing new strategies to produce high-performance lead-free oxide piezoelectrics with properties at least comparable to or surpassing those of the lead-based counterparts, such as PZT. [20] These strategies have mainly Piezoelectric materials are known to mankind for more than a century, with numerous advancements made in both scientific understandings and practical applications. In the last two decades, in particular, the research on piezoelectrics has largely been driven by the constantly changing technological demand, and the drive toward a sustainable society. Hence, environmental-friendly "lead-free piezoelectrics" have emerged in the anticipation of replacing lead-based counterparts with at least comparable performance. However, there are still obstacles to be overcome for realizing this objective, while the efforts in this direction already seem to culminat...

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“…In the past few decades, lead zirconate titanate (PZT) thin films with excellent piezoelectric properties have dominated the commercial market of piezoelectric thin film devices. However, the high content of toxic lead composition in PZT raises environmental and human health concerns, thus increasing efforts are made to develop high performance lead‐free piezoelectric thin films as replacements . Among lead‐free piezoelectric ceramics, potassium sodium niobate, (K, Na)NbO 3 (KNN), is one of the most promising candidates with competitive piezoelectric properties over a broad temperature range, as obtained in KNN‐based bulk ceramics by constructing phase coexistence with complex chemical compositions .…”

Section: Introductionmentioning

confidence: 99%

Outstanding Piezoelectric Performance in Lead‐Free 0.95(K,Na)(Sb,Nb)O₃‐0.05(Bi,Na,K)ZrO₃ Thick Films with Oriented Nanophase Coexistence

Wang

Qin

et al. 2019

Adv Elect Materials

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human health concerns, thus increasing efforts are made to develop high performance lead-free piezoelectric thin films as replacements. [6][7][8][9][10][11][12][13][14][15][16] Among lead-free piezoelectric ceramics, potassium sodium niobate, (K, Na)NbO 3 (KNN), is one of the most promising candidates with competitive piezoelectric properties over a broad temperature range, as obtained in KNN-based bulk ceramics by constructing phase coexistence with complex chemical compositions. [17][18][19][20][21][22] Compared to the bulk counterparts, it is much more challenging to achieve excellent piezoelectric properties in KNN-based thin films, because of the difficulties in controlling composition and phase coexistence with much more severe volatility issues, and more complicated stress and thickness effects. [6,13,16,[23][24][25] Our previous work provided an important technical solution to the above problems and achieved a very high effective piezoelectric strain coefficient, 33 eff d of 184 pm V −1 in solution-derived KNN-based thin films, with a complex leadfree composition of 0.95(K, Na)(Sb, Nb)O 3 -0.05(Bi, Na, K)ZrO 3 (KNSN-BNKZ0.05). [16] However, there was still a gap between this value and the highest 33 eff d (200-340 pm V −1 ) as reported in [100]-oriented polycrystalline PZT thin films on silicon. [26] The multiphase coexistence structure was not observed directly, although numerical simulation and X-ray diffraction results indicated an overall presence of different phases in the films. This work aims to demonstrate outstanding piezoelectric Lead-free 0.95(K 0.48 Na 0.52 )(Nb 0.95 Sb 0.05 )O 3 -0.05Bi 0.5 (Na 0.82 K 0.18 ) 0.5 ZrO 3 (KNSN-BNKZ0.05) piezoelectric films with preferred crystal orientation and enhanced thickness are fabricated on silicon substrates from a chemical solution approach. Adequate K excess is introduced to obtain a single perovskite phase in the resulting thicker films. The effects of thickness, crystal orientation, and structure of the films on the performance are investigated. Outstandingly large effective piezoelectric strain coefficient up to 250 pm V −1 is demonstrated over a macroscopic scale using a laser scanning vibrometer in the [100]-KNSN-BNKZ0.05 film with an enhanced thickness of 2.7 µm, competitive to the benchmark oriented lead zirconate titanate films on silicon. Atomically resolved electron microscopy reveals the coexistence of oriented ferroelectric rhombohedral (R) and tetragonal (T) phases at the nanometer scale with gradual polarization rotation, which can lower the domain wall energy and facilitate the large piezoelectric response. The increased film thickness reduces the in-plane mechanical clamping to enable more free deformation in the thickness direction and improve domain wall mobility, both further contributing to enhanced piezoelectric response.

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High‐Performance (Na_0.5K_0.5)NbO₃ Thin Film Piezoelectric Energy Harvester

Cited by 29 publications

References 40 publications

Resistive Switching Memory Integrated with Nanogenerator for Self‐Powered Bioimplantable Devices

Resistive Switching Memory Integrated with Nanogenerator for Self‐Powered Bioimplantable Devices

Evolution from Lead‐Based to Lead‐Free Piezoelectrics: Engineering of Lattices, Domains, Boundaries, and Defects Leading to Giant Response

Outstanding Piezoelectric Performance in Lead‐Free 0.95(K,Na)(Sb,Nb)O₃‐0.05(Bi,Na,K)ZrO₃ Thick Films with Oriented Nanophase Coexistence

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High‐Performance (Na0.5K0.5)NbO3 Thin Film Piezoelectric Energy Harvester

Cited by 29 publications

References 40 publications

Resistive Switching Memory Integrated with Nanogenerator for Self‐Powered Bioimplantable Devices

Resistive Switching Memory Integrated with Nanogenerator for Self‐Powered Bioimplantable Devices

Evolution from Lead‐Based to Lead‐Free Piezoelectrics: Engineering of Lattices, Domains, Boundaries, and Defects Leading to Giant Response

Outstanding Piezoelectric Performance in Lead‐Free 0.95(K,Na)(Sb,Nb)O3‐0.05(Bi,Na,K)ZrO3 Thick Films with Oriented Nanophase Coexistence

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Product

Resources

About

High‐Performance (Na_0.5K_0.5)NbO₃ Thin Film Piezoelectric Energy Harvester

Outstanding Piezoelectric Performance in Lead‐Free 0.95(K,Na)(Sb,Nb)O₃‐0.05(Bi,Na,K)ZrO₃ Thick Films with Oriented Nanophase Coexistence