Tuning the electronic structure of single-walled carbon nanotube by high-pressure H₂ exposure

Abstract

We report on an electronic structure change of single-walled carbon nanotube (SWNT) on hexagonal boron nitride due to electron doping via high-pressure H 2 exposure. The fractional coverage of hydrogenated carbon atom is estimated to be at least θ=0.163 from the in situ I ds -V g measurements of the release process. Raman spectroscopy and x-ray photoelectron spectroscopy were carried out to support the in situ electrical measurements. In particular, we used the dissociative Langmuir-type model to yield the desorption coefficient k des by fitting it to the in situ electrical data. Finally, we applied this hydrogenation method to the SWNT network on the commercial Si/SiO 2 substrate to open the possibility of the scalable n-type semiconducting SWNT FETs.

Enhanced Piezoelectric Performance of Electrospun PVDF‐TrFE by Polydopamine‐Assisted Attachment of ZnO Nanowires for Impact Force Sensing

“…As the (110)/(200) β ‐phase peak position does not shift after ZnO attachment to the PVDF‐TrFE EFs and subsequent hydrothermal treatment step, it can be concluded that the hydrothermal solution growth method is undertaken at a low enough temperature to not affect the PVDF‐TrFE crystal structure. [ 21 ]…”

“…An essential requirement for the advancement of continuous long‐term wearable devices is for electronics to be self‐powered and space‐efficient, without the need for bulky unsustainable batteries. Methods of self‐powering in research literature have included using materials that can harvest energy from the human body and ambient environment [ 20 ] (e.g., from light, [ 21 ] heat, [ 22,23 ] or mechanical force [ 24,25 ] ). In certain instances, energy harvesters can be used as active transducers for passive sensing by correlating the external stimuli (such as strain, [ 26–28 ] bending, [ 29 ] and impact force [ 30–34 ] ) to the generated output.…”

“…[ 47,51,52 ] The PVDF fibrous structure also provides a mechanically flexible and chemically resistant platform with a high surface‐to‐volume ratio, ideal for surface modifications and functionalizations. [ 21 ]…”

“…[ 53 ] It benefits from a wide bandgap (3.37 eV), low cost, ambient stability, biocompatibility, and simple crystal growth methods. [ 54 ] Electrospinning and ZnO nanomaterials have been used together extensively in research literature for a variety of applications such as energy harvesting, [ 29,32 ] photocatalytic sensing, [ 21,55,56 ] strain sensing, [ 26 ] field‐effect transistors, [ 57 ] pressure sensing, [ 58 ] and biosensing. [ 59 ] Addition of ZnO nanomaterials into PVDF systems, and their subsequent hydrothermal growth to increase ZnO crystal size, have been shown to enhance piezoelectric performance and voltage output.…”