nanostructured materials

Phonon polaritons (PhPs) have attracted significant interest in the nano-optics communities because of their nanoscale confinement and long lifetimes. Although PhP modification by changing the local dielectric environment has been reported, controlled manipulation of PhPs by direct modification of the polaritonic material itself has remained elusive.*

In the article “Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation” Yingjie Wu, Qingdong Ou, Yuefeng Yin, Yun Li, Weiliang Ma, Wenzhi Yu, Guanyu Liu, Xiaoqiang Cui, Xiaozhi Bao, Jiahua Duan, Gonzalo Álvarez-Pérez, Zhigao Dai, Babar Shabbir, Nikhil Medhekar, Xiangping Li, Chang-Ming Li, Pablo Alonso-González and Qiaoliang Bao demonstrate an effective chemical approach to manipulate PhPs in α-MoO3 by the hydrogen intercalation-induced perturbation of lattice vibrations.*

Their methodology establishes a proof of concept for chemically manipulating polaritons, offering opportunities for the growing nanophotonics community.*

The surface topography and near-field images presented in this article were captured using a commercial s-SNOM setup with a platinum iridium coated NanoWorld Arrow-NCPt AFM probe in tapping mode.*

Fig. 2 a) from “Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation” by Yingjie Wu et al. :
Reversible switching of PhPs in the L-RB of α-MoO3 a Schematic of the s-SNOM measurement and PhP propagation in a typical H-MoO3/α-MoO3 in-plane heterostructure.
2 a Schematic of the s-SNOM measurement and PhP propagation in a typical H-MoO3/α-MoO3 in-plane heterostructure. P — Fig. 2 a) from “*Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation*” by Yingjie Wu et al. :
Reversible switching of PhPs in the L-RB of α-MoO3 a Schematic of the s-SNOM measurement and PhP propagation in a typical H-MoO3/α-MoO3 in-plane heterostructure.
2 a Schematic of the s-SNOM measurement and PhP propagation in a typical H-MoO3/α-MoO3 in-plane heterostructure. Please follow this external link for the full figure: https://www.nature.com/articles/s41467-020-16459-3/figures/2

*Yingjie Wu, Qingdong Ou, Yuefeng Yin, Yun Li, Weiliang Ma, Wenzhi Yu, Guanyu Liu, Xiaoqiang Cui, Xiaozhi Bao, Jiahua Duan, Gonzalo Álvarez-Pérez, Zhigao Dai, Babar Shabbir, Nikhil Medhekar, Xiangping Li, Chang-Ming Li, Pablo Alonso-González & Qiaoliang Bao
Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation
Nature Communications volume 11, Article number: 2646 (2020)
DOI: https://doi.org/10.1038/s41467-020-16459-3

Please follow this external link to read the full article https://rdcu.be/b46eT

Open Access The article “ Chemical switching of low-loss phonon polaritons in α-MoO3 by hydrogen intercalation “ by Yingjie Wu, Qingdong Ou, Yuefeng Yin, Yun Li, Weiliang Ma, Wenzhi Yu, Guanyu Liu, Xiaoqiang Cui, Xiaozhi Bao, Jiahua Duan, Gonzalo Álvarez-Pérez, Zhigao Dai, Babar Shabbir, Nikhil Medhekar, Xiangping Li, Chang-Ming Li, Pablo Alonso-González and Qiaoliang Bao is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Nanostructured electrodes and their flexible integrated systems have great potential for many applications, including electrochemical energy storage, electrocatalysis and solid-state memory devices, given their ability to improve faradaic reaction sites by large surface area. Although many processing techniques have been employed to fabricate nanostructured electrodes on to flexible substrates, these present limitations in terms of achieving flexible electrodes with high mechanical stability.*

In the study “Flexible 3D Electrodes of Free-Standing TiN Nanotube Arrays Grown by Atomic Layer Deposition with a Ti Interlayer as an Adhesion Promoter” by Seokjung Yun, Sang-Joon Kim, Jaesung Youn, Hoon Kim, Jeongjae Ryu, Changdeuck Bae, Kwangsoo No and Seungbum Hong, the adhesion, mechanical properties and flexibility of TiN nanotube arrays on a Pt substrate were improved using a Ti interlayer. Highly ordered and well aligned TiN nanotube arrays were fabricated on a Pt substrate using a template-assisted method with an anodic aluminum oxide (AAO) template and atomic layer deposition (ALD) system.*

The authors show that with the use of a Ti interlayer between the TiN nanotube arrays and Pt substrate, the TiN nanotube arrays could perfectly attach to the Pt substrate without delamination and faceted phenomena. Furthermore, the I-V curve measurements confirmed that the electric contact between the TiN nanotube arrays and substrate for use as an electrode was excellent, and its flexibility was also good for use in flexible electronic devices. Future efforts will be directed toward the fabrication of embedded electrodes in flexible plastic substrates by employing the concepts demonstrated in this study.*

The presented strategy provides a new class of nanostructured 3D electrodes to overcome critical mechanical stability, thus providing a great potential platform for application in a flexible integrated device.*

Topography and transport properties were investigated using a conductive atomic force microscope with NanoWorld Pointprobe® EFM AFM probes ( Pt-coated conductive AFM tips).*

Figure 5 from “*Flexible 3D Electrodes of Free-Standing TiN Nanotube Arrays Grown by Atomic Layer Deposition with a Ti Interlayer as an Adhesion Promoter*” by Seokjung Yun et al.:
Analysis of TiN NTs/ Ti / Pt samples (a) XRD, (b) schematic of C-AFM setup, (c) AFM height image, and (d) local I-V curve by C-AFM.

*Seokjung Yun, Sang-Joon Kim, Jaesung Youn, Hoon Kim, Jeongjae Ryu, Changdeuck Bae, Kwangsoo No and Seungbum Hong
Flexible 3D Electrodes of Free-Standing TiN Nanotube Arrays Grown by Atomic Layer Deposition with a Ti Interlayer as an Adhesion Promoter
Nanomaterials 2020, 10, 409
DOI: 10.3390/nano10030409

Please follow this external link for access to the full article: https://doi.org/10.3390/nano10030409

Open Access The article “Flexible 3D Electrodes of Free-Standing TiN Nanotube Arrays Grown by Atomic Layer Deposition with a Ti Interlayer as an Adhesion Promoter“ by Seokjung Yun, Sang-Joon Kim, Jaesung Youn, Hoon Kim, Jeongjae Ryu, Changdeuck Bae, Kwangsoo No and Seungbum Hong is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.