Electricity Generation based on One‐Dimensional Group‐III Nitride Nanomaterials

Abstract

In nanoscience and nanotechnology, it is very attractive to develop self-powered nanodevices with the use of nanogenerators replacing batteries. In this way, one could realize independent and continuous operations of implantable biosensors, microelectromechanical systems, nanorobots and even portable personal electronics.[1] Moreover, due to the current energy crisis, it would be even more alluring if the generators can harvest the wasted energy in the environment, such as body-movement, light wind and vibration of acoustic waves.[2] By focusing on these applications, great progress has been made in developing piezoelectric nanogenerators using ZnO nanowires, [3] CdS nanowires, [4] ZnS nanowires, [5] PZT nanofibers, [6] and GaN nanorods, [7] which give great promise for the integration of piezotronics and nanoelectronics.Group-III nitride semiconductors, highlighted for their tunable, direct band gap and good chemical stability, [8] also have a pronounced piezoelectric property owing to their wurtzite crystal structures. In terms of the coupling between their piezoelectric and semiconducting properties, an output power should be generated by scanning an atomic force microscope (AFM) tip in contact mode across 1D group-III nitride nanomaterials. In this study, a family of 1D group-III nitrides, including AlN and AlGaN nanocones, GaN nanorods and InN nanocones, are synthesized through a facile chemicalvapor-deposition (CVD) route based on previous work. [9] Increasing electricity generation is demonstrated following the sequence: AlN, AlGaN, GaN and InN, which can be attributed to the increasing piezoelectric potential and carrier density. These results not only extend piezotronics to a new domain of group-III nitrides, but also deepen the understanding of the underlying physics of piezoelectric nanogenerators. Figure 1 shows scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of the quasialigned arrays of AlN nanocones, AlGaN nanocones, GaN nanorods and InN nanocones, with diameters at the middle of around 100, 70, 500, and 700 nm, and the lengths of about 2, 1, 3.5, and 4 mm, respectively. The nanostructures preferentially stand perpendicularly on the Si substrates. Due to the relatively large sizes of the GaN nanorods and InN nanocones, their hexagonal intersections are obvious, and are determined by their common family crystal structure.[10] The corresponding highresolution transmission electron microscopy (HRTEM) images and selected-area electron-diffraction (SAED) patterns (insets of Fig. 1b, 1d [11] GaN, and InN, respectively. X-ray diffraction (XRD) profiles of these samples are shown in Figure 2, and could be indexed to hexagonal wurtzite AlN, Al 0.33 Ga 0.67 N (based on Vegard's law [12] ), GaN and InN (JCPDS card No 65-0832, 50-0792, 50-1239). The much-stronger intensity of the (002) peak relative to the corresponding standard diffraction pattern indicates preferential growth along the c-axis, [9] in agreement with the SAED patterns.In the demonstration of piezoelectric ...

Inducing a Finite In-Plane Piezoelectricity in Graphene with Low Concentration of Inversion Symmetry-Breaking Defects

“…60 Computed counterparts do agree with to BNG structures with p multiple of 3, such as (1,1), (1,4) and (1,7). The nuclear relaxation effect is seen to be quite small in all cases if compared with the electronic one: it never counts more than 3.8% for the dominant C 11 constant, which occurs for the (1,1) BNG structure of highest BN concentration.…”

“…[1][2][3] A variety of NEMS devices has been successfully produced (nanosized switches, sensors, motors, energy harvesters, actuators, etc.) [4][5][6][7] which essentially rely on quantum-size effects. 8 Most of such devices require some sort of dynamical control of atomic displacements and nanoscale deformations.…”

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…Following this initial discovery, both direct current [23,499,500] and alternating current [24] ZnO nanogenerators have been developed. In addition, nanogenerators based on other materials, such as GaN nanowires [501][502][503], InN nanowires [504], AlGaN nanocones [505], CdS nanowires [506], ZnO/ZnS heterojunction nanowires [507], lead zircornia titanates (PZT) nanofibers [508], nanoribbons [509][510][511][512][513], nanotubes [514], and single crystalline nanowires [515], BaTiO 3 nanowires [516], NaNbO 3 nanowires [517], and poly(vinylidene fluoride) (PVDF) nanofibers [518,519], have shown promising potential for enhancing nanogenerator performance. Consequently, a worldwide effort has been launched in this regard, forming a new research field in nanotechnology and energy science [520].…”

Robust optimization of the output voltage of nanogenerators by statistical design of experiments

“…A challenging issue affecting potential applications of nanogenerators is their low power output. In an attempt to obtain higher power output, p-type ZnO nanowire arrays, ZnS nanowires and other materials have all been used to fabricate nanogenerators [9][10][11][12], using a variety of different physical designs. However, a systematic study is still required in order to examine the influence of key parameters-such as the input mechanical force and electrode abrasion-on the output of a nanogenerator.…”