Search query: piezoelectric effects in pyroelectric

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abstract: We examine the effects of a uniform temperature change on PN junctions in piezoelectric semiconductor fibers. A one dimensional model for thermally induced extensional deformation of the fibers derived previously from the macroscopic theory of thermopiezoelectric semiconductors is employed. With the linearized model, we present the analytical expressions of the built in potential, carrier distribution, electric field, and polarization field in piezoelectric semiconductor PN junctions. A combined analytical and numerical analysis is performed on the built in electromechanical fields in the junctions and their current voltage relations. Numerical results show that homogeneous junctions have relatively good temperature stability, but heterogeneous junctions are sensitive to a temperature change that may be explored for thermally manipulating piezotronic devices. The difference between the temperature behaviors of the two types of junctions is determined to be due to the net amount of effective polarization charges at the junctions through pyroelectric and combined thermoelastic piezoelectric couplings.
author_names: Ruo-ran Cheng

Chunli Zhang

Weiqiu Chen

Jiashi Yang
title: Temperature Effects on PN Junctions in Piezoelectric Semiconductor Fibers with Thermoelastic and Pyroelectric Couplings
venue: Journal of Electronic Materials
year: 2020

abstract: Interfaces in heterostructures have been a key point of interest in condensed matter physics for decades owing to a plethora of distinctive phenomena such as rectification1, the photovoltaic effect2, the quantum Hall effect3 and high temperature superconductivity4 and their critical roles in present day technical devices. However, the symmetry modulation at interfaces and the resultant effects have been largely overlooked. Here we show that a built in electric field that originates from band bending at heterostructure interfaces induces polar symmetry therein that results in emergent functionalities, including piezoelectricity and pyroelectricity, even though the component materials are centrosymmetric. We study classic interfaces namely, Schottky junctions formed by noble metal and centrosymmetric semiconductors, including niobium doped strontium titanium oxide crystals, niobium doped titanium dioxide crystals, niobium doped barium strontium titanium oxide ceramics, and silicon. The built in electric field in the depletion region induces polar structures in the semiconductors and generates substantial piezoelectric and pyroelectric effects. In particular, the pyroelectric coefficient and figure of merit of the interface are over one order of magnitude larger than those of conventional bulk polar materials. Our study enriches the functionalities of heterostructure interfaces, offering a distinctive approach to realizing energy transduction beyond the conventional limitation imposed by intrinsic symmetry. A built in electric field at the interface of metals and centrosymmetric semiconductors is shown to induce polar structures in the semiconductors and generate substantial piezoelectric and pyroelectric effects.
author_names: Ming-Min Yang

Zheng-Dong Luo

Zhou Mi

Jinjin Zhao

Sharel P E

Marin Alexe
title: Piezoelectric and pyroelectric effects induced by interface polar symmetry
venue: Nature
year: 2020

abstract: Abstract Gallium nitride (GaN) nanowires and nanotubes possess extraordinary device ability of converting wasted energy into harvestable electricity in terms of their piezoelectricity and pyroelectricity. From the perspective of atomic cohesive energy, we present a model to clarify the physical origin of the size and shape dependency of the piezoelectric and pyroelectric properties for intrinsic GaN nanowires and nanotubes. It is shown that both the piezopotential and the pyropotential increase with the inverse of GaN nanocrystal size or with the shape factor. The influence of size and shape becomes more significant for nanotubes with smaller size or wall thick to size ratio and may enhance both potentials by up to dozens of times or even more. Such size and shape effects originate from the synergetic effects of nanoscale dielectricity, piezoelectricity and thermoelasticity where the piezoelectricity plays a more important role than the other two factors. Moreover, high piezopotential and pyropotential in GaN nanotubes render them appealing in the design of novel nanogenerators in comparison with the most commonly used nanowires.
author_names: Haiping Jiang

Yingjie Su

Jia Zhu

Haiming Lu

Xiangkang Meng
title: Piezoelectric and pyroelectric properties of intrinsic GaN nanowires and nanotubes: Size and shape effects
year: 2018

abstract: A hybridized nanogenerator is demonstrated, which has the structure of PVDF nanowires PDMS composite film/indium tin oxide (ITO) electrode/polarized PVDF film/ITO electrode, and which can individually/simultaneously scavenge mechanical and thermal energies using piezoelectric, triboelectric, and pyroelectric effects. As compared with the individual energy harvesting unit, the hybridized nanogenerator has a much better charging performance. This work may push forward a significant step toward multienergy harvesting technology.
author_names: Shuhua Wang

Zhong Lin Wang

Ya Yang
title: A One Structure Based Hybridized Nanogenerator for Scavenging Mechanical and Thermal Energies by Triboelectric Piezoelectric Pyroelectric Effects.
venue: Advanced materials
year: 2016

abstract: Abstract Materials like the Macro fiber Composite (MFC) are employed in energy harvesting applications utilizing the piezoelectric effect. However, energy harvesting using the pyroelectric effect in MFCs is an unexplored topic. This paper takes strides in understanding the thermal micromechanical interactions that MFCs experience due to this effect and leads to a better understanding of how MFCs behave in thermal environments. In this work, the pyroelectric coefficient (primary and secondary) are estimated for P1 and P2 Macro fiber Composites (MFCs) using micromechanical modeling and experimental techniques. The coefficient of thermal expansion (CTE) is estimated using micromechanical theory for both MFC types which is consequently used in the modeling of the pyroelectric coefficient. Secant based moduli are used to better approximate the properties of components of MFCs in the regime of linear elasticity. Two experiments are conducted to measure the pyroelectric coefficient under different boundary conditions. In the first experiment, the thermal expansion of the MFC is constrained in a Kevlar envelope, while in the second experiment, the MFC is epoxied onto a metal shim allowing restricted deformations. Thermal experiments were conducted in an altitude chamber where the resulting average pyroelectric coefficient is calculated for both experiments.
author_names: Krystal L Acosta

Siddharth Srivastava

William Keats Wilkie

Daniel J Inman
title: Primary and secondary pyroelectric effects in macro fiber composites
venue: Composites Part B: Engineering
year: 2019

abstract: Abstract A transient voltage is observed between c axis contacts of a YBa 2 Cu 3 O 7 d d 0.1) single crystal upon application of a heat pulse (either generated thermally or by laser absorption) A similar transient voltage appears when stress is applied to the sample. We have not been able to observe either effect in insulating YBa 2 Cu 3 O 7 d d =0.7) We suggest that the thermally induced voltage is a pyroelectric effect and that the stress induced voltage is a piezoelectric effect, implying the existence of a macroscopic polarization in the material. We discuss possible mechanisms for charge symmetry breaking (involving the apex O(4) oxygen atom) which would give rise to a macroscopic polarization along z in the YBa 2 Cu 3 O 7 structure.
author_names: Dragan Mihailovic

Alan J Heeger
title: Pyroelectric and piezoelectric effects in single crystals of YBa2Cu3O7 d
year: 1990

abstract: Abstract To minimize pyroelectric effects while keeping high piezoelectric effects in relaxor PbTiO 3 single crystals, the crystallographic orientation dependence of the pyroelectric and piezoelectric coefficients were investigated for binary (1 x )Pb(Mg 1/3 Nb 2/3 )O 3 x PbTiO 3 (PMN PT) ternary (1 x y )Pb(In 1/2 Nb 1/2 )O 3 y Pb(Mg 1/3 Nb 2/3 )O 3 x PbTiO 3 (PIN PMN PT) and Mn doped PIN PMN PT single crystals with the "4R" multidomain state. The secondary pyroelectric coefficients were calculated from the thermodynamic inter relationship between the piezoelectric, elastic, and thermal expansion coefficients, being on the order of (1.16 1.23) x 10 4 C m 2 K 1 for binary crystals and (0.97 2.03) x 10 4 C m 2 K 1 for ternary ones. The primary pyroelectric coefficients were (6.73 6.84) x 10 4 C m 2 K 1 and (5.44 6.43) x 10 4 C m 2 K 1 for binary and ternary crystals, respectively. The pyroelectric coefficients could be reduced by matrix rotation, but at the cost of decreasing longitudinal piezoelectric coefficients d 33 Of particular interest is that the maximum piezoelectric coefficients d 24 at th 55 o and d 34 at th 35 o by a counterclockwise rotation of th about the X axis th is the rotation angle about the coordinate axes) or d 15 at th 55 o and d 35 at th 35 o by a counterclockwise rotation the Y axis, were found on the order of 3000 pC N 1 The corresponding pyroelectric coefficients could be reduced by ~20% The reduced pyroelectric coefficients that can contribute to decrease undesirable output signals, together with the high piezoelectric coefficients, enable relaxor PT crystals as favorable candidates for high sensitivity piezoelectric sensors.
author_names: Yanxue Tang

Zong-Yang Shen

Shujun Zhang

Wen-hua Jiang

Jun Luo

Thomas R Shrout
title: Minimization of pyroelectric effects in relaxor PbTiO3 crystals for piezoelectric sensors
year: 2014

abstract: Lead free sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) nanoceramics synthesized by sol gel method were doped with CeO2 by using solid state method from 0.0 to 5.0 wt% The effects of CeO2 doped NBT on structure and microstructure as well as electrical properties were investigated. X ray analysis shows that CeO2 diffuses into the lattice of NBT to form a solid solution and form morphotropic phase boundary between rhombohedral and tetragonal phase structure in NBT during the sintering process. The electrical properties of NBT ceramics have been greatly improved by doping certain amount of CeO2. The NBT 0.6 wt% CeO2 shows improvement in dielectric properties at room temperature with the highest dielectric constant at 10 kHz (em' 1276, tan d 0.03 and Tm 370 degC) high remanent polarization (Pr 56 mC cm 2) and low coercive field (Ec 53 kV cm 1) Piezoelectric properties were enhanced with the doping, where the piezoelectric constant d33 90 pC N 1 and enhance in mechanical coupling factor k33 0.44. The results suggest that the NBT 0.6 CeO2 ceramics can be a suitable material for sensor, actuator or memory device application.
author_names: N A Halim

Wan Haliza Abd Majid

T S Velayutham
title: Ferroelectric, pyroelectric and piezoelectric properties of CeO2 doped Na0.5Bi0.5TiO3 ceramics
venue: SN Applied Sciences
year: 2019

abstract: This work proposes an enhanced method for thermal energy harvesting exploiting combined pyroelectric, piezoelectric and shape memory (SME) effects, and presents its experimental validation. A material which is pyroelectric is also piezoelectric. If it is combined with a material with SME, which generates large strain and stress in a rather narrow temperature range, the resulting composite material would generate voltage from temperature variations using two different energy conversion principles at once: (1) pyroelectric effect, (2) piezoelectric effect driven by SME. A Macro Fiber Composite piezoelectric was shown here to exhibit significant pyroelectric effect ~4 V/degC) When combining it with a SME Ti Ni Cu alloy into a laminated structure, this effect increased by 50% This increase may be an order of magnitude higher for an optimized system. Such composites open an opportunity to harvest thermal energy from natural sources, since this method can increase the rather low efficiency of current pyroelectric materials especially for small temperature variations.
author_names: D I Zakharov

Boris Gusarov

Elena B Gusarova

Bernard Viala

Orphee Cugat

J Delamare

Leticia Gimeno
title: Combined Pyroelectric, Piezoelectric and Shape Memory Effects for Thermal Energy Harvesting
year: 2013

abstract: Piezoelectric and pyroelectric materials are used in many current applications. The purpose of this paper is to explain the basic properties of pyroelectric and piezoelectric effects and demonstrate them in simple experiments. Pyroelectricity is presented on lead zirconium titanate (PZT) ceramics as an electric charge generated by the temperature change. The direct piezoelectric effect is demonstrated by the electric charge generated from the bending of the piezoelectric ceramic membrane or from the gas igniter. The converse piezoelectric effect is presented in the experiments by the deflection of the bending piezoelectric element (piezoelectric bimorph)
author_names: Jiri Erhart
title: Experiments to demonstrate piezoelectric and pyroelectric effects
year: 2013