Highly Durable Piezoelectric Nanogenerator by Heteroepitaxy of GaN Nanowires on Cu Foil for Enhanced Output Using Ambient Actuation Sources

Abstract

Highly durable piezoelectric nanogenerators (PENGs) with high conversion efficiency and high power density are of great interest. Here, a foldable, scalable, durable, cost‐effective, sensitive, and high current output PENG developed by the direct integration of van der Waals heteroepitaxial growth of GaN nanowires (NWs) by metal‐organic chemical vapor deposition using a graphene coating on a Cu‐foil is reported where the direct growth of GaN on the metallic substrate plays a key role in achieving the high stability of the PENG. The PENG provides a durable and highly sensitive output compared to the previously reported GaN NW‐based PENGs fabricated by transferring NWs onto a foreign substrate. The reported PENG can harvest energy from a variety of ambient actuation sources such as bending, vibrations, air flow, finger pressing, foot striking, fluid flow, and normal force by weights, with the maximum piezoelectric output voltage and current density recorded as 19.7 V and 1.9 mA cm−2, respectively. Due to its high conversion efficiency, the PENG can power several LEDs and thus can be used to power electronic devices. More importantly, the PENG retains its performance after more than 4 million actuation cycles, demonstrating the potential of the design for practical applications using biomechanical and ambient actuation sources for self‐powered systems.

High Performance, Stable, and Flexible Piezoelectric Nanogenerator Based on GaN:Mg Nanowires Directly Grown on Tungsten Foil

“…As reported in our preliminary study, polyethylene terephthalate (PET) substrate was attached to the backside of Cu-foil to make the PNG elastic. [28] In this study, we proposed the direct growth of Mg-doped semi-insulating GaN (GaN:Mg) NWs on a 30-µm-thick tungsten foil using metalorganic chemical vapor deposition (MOCVD). Tungsten foil is more suitable than any other metal foil for direct growth of NWs without any insertion layer because of tungsten's higher melting point (≈3400 °C), lowest coefficient of thermal expansion, highest tensile strength, and lowest vapor pressure, compared to all other metals.…”

Perspective on the development of high performance flexible piezoelectric energy harvesters

“…7(a-f). 128 Under a bending motion, the corresponding device exhibits high electrical output shown in Fig. 7(g-i).…”

“…FPEHs based on 1-3 piezoelectric/polymer composites have received much attention for high performance and various applications. [122][123][124][125][126][127][128][129][130] In a 1-3 type architecture, the piezoelectric (ceramic/semiconductor) has connectivity in one direction as schematically shown in Fig. 6a.…”

Ultra-Stable and Durable Piezoelectric Nanogenerator with All-Weather Service Capability Based on N Doped 4H-SiC Nanohole Arrays

“…Due to the complexity of the Earth's environment, such as from − 70 °C in polar region to 60 °C in Africa, from 0% relative humidity (RH) in desert to 100% RH in rainforest, the PENG with all-weather service capability is in urgent need of development. So, the standards required for piezoelectric materials used to assemble all-weather service PENG, such as chemical and thermal stability, environmental friendliness and durability, have become the main obstacles restricting their wide application [ 6 ]. The piezoelectric polymer, for example, PVDF, P(VDF-TrFE) and PVDF-HFP, can’t be applied in extreme temperature environments due to thermal instability [ 7 – 10 ].…”