Piezoelectricity in Multilayer Black Phosphorus for Piezotronics and Nanogenerators

Abstract

Recently, piezoelectric characteristics have been a research focus for 2D materials because of their broad potential applications. Black phosphorus (BP) is a monoelemental 2D material predicted to be piezoelectric because of its highly directional properties and non‐centrosymmetric lattice structure. However, piezoelectricity is hardly reported in monoelemental materials owing to their lack of ionic polarization, but piezoelectric generation is consistent with the non‐centrosymmetric structure of BP. Theoretical calculations of phosphorene have explained the origin of piezoelectric polarization among P atoms. However, the disappearance of piezoelectricity in multilayer 2D material generally arises from the opposite orientations of adjacent atomic layers, whereas this effect is limited in BP lattices due to their spring‐shaped space structure. Here, the existence of in‐plane piezoelectricity is experimentally reported for multilayer BP along the armchair direction. Current–voltage measurements demonstrate a piezotronic effect in this orientation, and cyclic compression and release of BP flakes show an intrinsic current output as large as 4 pA under a compressive strain of −0.72%. The discovery of piezoelectricity in multilayer BP can lead to further understanding of this mechanism in monoelemental materials.

Up-scalable emerging energy conversion technologies enabled by 2D materials: from miniature power harvesters towards grid-connected energy systems

“…21,39,44,45,[63][64][65][66][67][68][69][70][71][72][73] In this review, we summarize the recent developments on the utilisation of GRM in emerging energy conversion device applications, mainly highlighting the high potential of this approach towards on-grid energy generation. Our approach bridges the wellexplored area of developing small-scale GRM-enabled energy harvesters for powering IoT devices, 1,5,7,17,19,35,[74][75][76][77][78][79][80][81][82] with recent research directions on GRM-enabled large-scale energy conversion installations. First, the whole bouquet of the emerging properties expected at the 2D limit of GRM intimately coupled to smart energy harvesting are discussed.…”

“…22,24,[88][89][90][91][92][93][94][95][96][97][98][99] Ever since the discovery of graphene, plenty of 2D materials have been investigated, such as graphene oxide (GO) and derivatives, [100][101][102] graphdiyne, 103 group-VA semiconductors, 104 phosphides, 105 transition metal dichalcogenides (TMDC), [106][107][108][109][110] transition metal carbides/carbonitrides (MXenes) 78,[111][112][113] and black phosphorous (BP), just to name a few. 74,87,114,115 The absence of an inherent E G in graphene restricts its applicability Fig. 2 GRM's emerging properties at 2D limit.…”

Bioelectronics‐Related 2D Materials Beyond Graphene: Fundamentals, Properties, and Applications

“…Under a compressive strain of −0.72%, the device showed an intrinsic output current of 4 pA and was concluded to hold great promise for the construction of biomechanical energy-harvesting devices. [293] Flexible thermoelectric materials are also important components of flexible power supply devices. For example, Guo et al built a heterojunction system by decorating 2D MoS 2 with Au nanoparticles using an in situ growth method.…”

“…Under a compressive strain of −0.72%, the device showed an intrinsic output current of 4 pA and was concluded to hold great promise for the construction of biomechanical energy‐harvesting devices. [ 293 ]…”

Synthesis Techniques, Optoelectronic Properties, and Broadband Photodetection of Thin‐Film Black Phosphorus

“…Recently, monoelemental vdW layered materials, such as black phosphorus (BP, Figure 3a), [ 28–33 ] boron, [ 34,35 ] arsenene, [ 36,37 ] tellurium, [ 38,39 ] antimonene, [ 40–43 ] and bismuthine, [ 44,45 ] attract great attentions from researchers. BP stands out among various layered materials due to its modest bandgap, [ 46,47 ] high light absorption, [ 33,48 ] high room‐temperature carrier mobility (≈5000 cm 2 V −1 s −1 ), [ 49–52 ] and nice biological compatibility, [ 53 ] which make it a candidate to apply in various devices, [ 54–56 ] such as photodetector, [ 46,48,57–62 ] ultrafast laser, [ 63–65 ] optical switching, [ 66 ] modulator, [ 67 ] sensor, [ 68 ] and even biomedicine. [ 69–71 ] Intrinsic BP flake possesses a thickness‐dependent direct bandgap from 0.3 eV (bulk) to 2.0 eV (monolayer), corresponding to a maximum photoresponse cutoff wavelength of 4 µm.…”