Multieffect Coupled Nanogenerators

Abstract

With the advent of diverse electronics, the available energy may be light, thermal, and mechanical energies. Multieffect coupled nanogenerators (NGs) exhibit strong ability to harvest ambient energy by integrating various effects comprising piezoelectricity, pyroelectricity, thermoelectricity, optoelectricity, and triboelectricity into a standalone device. Interaction of multitype effects can promote energy harvesting and conversion by modulating charge carriers’ behaviour. Multieffect coupled NGs stand for a vital group of energy harvesters, supporting the advances of an electronic device and promoting the resolution of energy crisis. The matchless versatility and high reliability of multieffect coupled NGs make them main candidates for integration in complicated arrays of the electronic device. Multieffect coupled NGs can also be employed as a variety of self-powered sensors due to their rapid response, high accuracy, and high responsivity. This article reviews the latest achievements of multieffect coupled NGs. Fundamentals mainly including basic theory and materials of interest are covered. Advanced device design and output characteristics are introduced. Potential applications are described, and future development is discussed.

Ferroelectric Materials Based Coupled Nanogenerators

“…Annealing of these systems at high temperatures crystalizes them in the γ-phase, which also has a net dipole moment perpendicular to the carbon backbone and is polar. Orthorhombic β-phase can be achieved by stretch or draw in previously derived phases and is an all-trans configuration with high spontaneous polarization and a dielectric constant [85]. So, electric poling makes β-PVDF-phase a strong piezoelectric and pyroelectric phase, when compared with other polymorphs.…”

“…Ferroelectric materials (such as PZT, KNN, and PMN) with morphotropic (MPB) or polymorphic phase boundary (PPB) relate to the rotation of polarization and indicate the presence of multiple phases within the material, show exceptional piezoelectric response, and piezoelectric coefficient [113,114] BTO; PVDF has also been studied widely in piezoelectric harvesters of mechanical energies, known as piezoelectric nanogenerators (PENG). The operational mechanism of ferroelectric PENG is based on the volume density model; that is, compressing the ferroelectric dipole density increases over the reduced material thickness and stretching material dipole density declines over increased material thickness [85,115]. Consequently, ferroelectric material polarization changes as dipole density vary and results in the generation of the piezoelectric signal.…”

Dielectric Manipulated Charge Dynamics in Contact Electrification

“…Contact electrification brings about charge transfer between two materials during contact or friction process [1][2][3], and this universally existing phenomenon is also considered to be derived from the difference of work functions or surface potentials between the contacting materials [4][5][6]. Though the triboelectric charges are commonly regarded to be detrimental for electronic circuits and systems, they have been successfully utilized in today's advanced technologies, including photocopying [7], laser printing [8], electrostatic separation [9], painting [10], field-effect transistor [11][12][13], and mechanical energy harvesting [14][15][16].…”

Growth, Properties and Applications of Bi0.5Na0.5TiO3 Ferroelectric Nanomaterials

“…As fascinating multifunctional materials, ferroelectrics have been widely utilized in optoelectronic devices [1,2], capacitors [3], energy harvesters [4,5], oscillators [6], transducers [7] and sensors [8,9]. For a long time, Pb(Zr x Ti 1−x )O 3 (PZT) ferroelectric materials have been intensively investigated since they possess large piezoelectric coefficient together with high Curie temperature.…”