Strong tribo-piezoelectric effect in bilayer indium nitride (InN)

Abstract

The high electronegativity between the atoms of two-dimensional (2D) group-III nitrides makes them attractive to demonstrating a strong out-of-plane piezo-electricity effect. Energy harvesting devices can be predicted by cultivating such salient piezoelectric features. This work explores the tribo-piezoelectric properties of 2D-indium nitride (InN) as a promising candidate in nanogenerator applications by means of first-principles calculations. In-plane interlayer sliding between two InN monolayers leads to a noticeable rise of vertical piezoelectricity. The vertical resistance between the InN bilayer renders tribological energy by the sliding effect. During the vertical sliding, a shear strength of 6.6–9.7 GPa is observed between the monolayers. The structure can be used as a tribo-piezoelectric transducer to extract force and stress from the generated out-of-plane tribo-piezoelectric energy. The A–A stacking of the bilayer InN elucidates the highest out-of-plane piezoelectricity. Any decrease in the interlayer distance between the monolayers improves the out-of-plane polarization and thus, increases the inductive voltage generation. Vertical compression of bilayer InN produces an inductive voltage in the range of 0.146–0.196 V. Utilizing such a phenomenon, an InN-based bilayer compression-sliding nanogenerator is proposed, which can tune the generated tribo-piezoelectric energy by compressing the interlayer distance between the InN monolayers. The considered model can render a maximum output power density of ~ 73 mWcm−2 upon vertical sliding.

Effects of the Substrate Structure on the CVD Growth of Two-Dimensional Hexagonal Boron Nitride

“…The epitaxial growth of single-crystal graphene on a macrosized (up to 0.5 m) single-crystal Cu(111) foil has recently been achieved, opening the door for the epitaxial growth of single crystals of other promising two-dimensional (2D) materials. − In particular, significant effort has been given to achieving the growth of wafer scale 2D hexagonal boron nitride ( h -BN) because of its outstanding electrical, mechanical, , thermal, − optical, and chemical properties. − Although top-down processes such as mechanical or watery exfoliation make it easy to produce high-grade h -BN, the exfoliated flake size is small and the thickness varies greatly, restricting the development of practical applications. The bottom-up strategy such as chemical vapor deposition (CVD) is the most favorable approach owing to its mass fabrication capability and variable controllability through the growth phase.…”

Tensile Mechanical Behavior and the Fracture Mechanism in Monolayer Group-III Nitrides XN (X= Ga, In): Effect of Temperature and Point Vacancies

“… 13 − 16 Moreover, employing a surface-confined nitridation technique, micrometer-sized 2D-GaN has been synthesized recently. 17 , 18 InN-based nanostructures 19 , 20 are also improving day by day. Therefore, the application prospects of monolayer XN in the field of NEMS such as nanoenergy harvesting, energy storage, sensing, and piezotronics are exciting, and the investigation of the mechanical properties at different circumstances attracts great attention.…”

“… 36 − 42 Moreover, a van der Waals heterobilayer built by XN has also been explored recently. 20 From these studies, it has been found that monolayer XN is very much promising and can be successfully employed in different piezoelectric, optoelectronic, photocatalytic, and sensing applications. Although most of the existing works has focused on studying the structural, electronic, and optical properties of XN, to the greatest of our understanding no studies have reported on the tensile mechanical behavior of this prospective monolayer.…”

“…13−16 Moreover, employing a surface-confined nitridation technique, micrometer-sized 2D-GaN has been synthesized recently. 17,18 InN-based nanostructures 19,20 are also improving day by day.…”

“…Since the exfoliation of graphene, , the very first two-dimensional (2D) materials with a honeycomb structure, a new milestone has been achieved to solve the failure problems of NEMS by using the extraordinary mechanical strength of graphene. , However, the zero electronic band gap of graphene is a major limitation in all of these prospects and triggered the scientists to invent other monolayer systems with comparable behavior like graphene. Recently, monolayer group III-nitrides XN (X = Ga, In) have shown promising potential in nanoscale device fabrication owing to their outstanding electronic, piezoelectric, optical, thermal, and mechanical properties. − Although the fabrication of monolayer XN from its bulk counterpart was a great challenge, recently, using the graphene encapsulation technique and molecular beam epitaxy method, the experimental fabrication of monolayer XN has been done. − Moreover, employing a surface-confined nitridation technique, micrometer-sized 2D-GaN has been synthesized recently. , InN-based nanostructures , are also improving day by day. Therefore, the application prospects of monolayer XN in the field of NEMS such as nanoenergy harvesting, energy storage, sensing, and piezotronics are exciting, and the investigation of the mechanical properties at different circumstances attracts great attention.…”