Versatile Graphene Nanoribbons and Quantum Chiral Nanocarbons
Wenhui Niu
Max Planck Institute of Microstructure , Halle

Thu., Jan. 11, 2024, 1 p.m.
This seminar is held in presence and online.
Room: HAL 115
Online: Zoom link of our Chair


In the first of the talk, we will focus on the topological engineering of graphene nanoribbons (GNRs) with tailor-made optoelectronic properties. GNRs, as quasi-one-dimensional graphene cutouts, have drawn growing attention as promising candidates for next-generation electronic and spintronic materials. However, the strong π-π interaction of GNRs prevents liquid-phase dispersibility, corresponding to severe aggregates with bad dispersibility in organic solvents, which significantly impedes their fundamental physiochemical studies as well as promising applications in nanoelectronics. To improve the dispersibility and to engineer the optoelectronic properties of GNRs, here we have developed the strategy of topological engineering of GNRs and synthesized a series of novel GNRs including bulky group functionalized GNR, porous GNR and curved GNR which present interesting properties and hold great potential in nanoelectronics devices.
In the second of the talk, we will focus on the chiral nanocarbons with unique chiroptical properties as well as interesting spin polarization. Chiral nanocarbons have attracted growing attention due to their exotic 3D structure, inherent chirality, and intriguing optoelectronic properties, in particular, their unique chiral-induced spin selectivity (CISS) effect. Due to the unique structural tunability and the specificity of quantum sensing, chiral nanocarbons have the potential to be a transformative tool in the next generation of quantum applications. Among them, helical nanographenes (NGs) featuring multi-layer topology have been considered as promising candidates for understanding the intricate interplay between the chiral structure and chiroptical properties/spin polarization. Herein, we demonstrate the modular synthetic strategy to construct a series of novel helical NGs with bilayer, trilayer, and tetralayer structures. The resultant NGs exhibit excellent circular dichroism (CD) and circularly polarized luminescence (CPL) responses with unprecedented high CPL brightness, rendering them promising candidates for CPL emitters. More interestingly, with the cooperation with Prof. Ron Naaman’s group, the magnetoresistance (MR) measurements were performed to investigate the spin polarization of our chiral molecules, which proves the clear CISS effect of our helical NGs.


Brief CV

Dr. Wenhui Niu studied polymer engineering at Sichuan University and obtained her Bachelor’s degree in 2016. From 2016, she started her PhD in chemistry from Shanghai Jiao Tong University under the supervision of Prof. Yiyong Mai. Between 2017 and 2020, she joined Prof. Xinliang Feng’s group as an exchange PhD student. In 2021, she received her PhD degree and joined the group of Prof. Xinliang Feng and continued her academic research as a postdoctoral fellow at Technische Universität Dresden for one year. In 2022, she joined the Max Planck Institute of Microstructure Physics and she was appointed as research group leader of “Quantum Chiral Nanocarbons” subgroup, where she focuses on the exploitation of novel chiral nanographenes with excellent chiroptical properties and unique spin polarization. In 2023, she received the Minerva Fast Track fellowship from the Max Planck Society.



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Versatile Graphene Nanoribbons and Quantum Chiral Nanocarbons
Wenhui Niu
Max Planck Institute of Microstructure , Halle

Thu., Jan. 11, 2024, 1 p.m.
This seminar is held in presence and online.
Room: HAL 115
Online: Zoom link of our Chair


In the first of the talk, we will focus on the topological engineering of graphene nanoribbons (GNRs) with tailor-made optoelectronic properties. GNRs, as quasi-one-dimensional graphene cutouts, have drawn growing attention as promising candidates for next-generation electronic and spintronic materials. However, the strong π-π interaction of GNRs prevents liquid-phase dispersibility, corresponding to severe aggregates with bad dispersibility in organic solvents, which significantly impedes their fundamental physiochemical studies as well as promising applications in nanoelectronics. To improve the dispersibility and to engineer the optoelectronic properties of GNRs, here we have developed the strategy of topological engineering of GNRs and synthesized a series of novel GNRs including bulky group functionalized GNR, porous GNR and curved GNR which present interesting properties and hold great potential in nanoelectronics devices.
In the second of the talk, we will focus on the chiral nanocarbons with unique chiroptical properties as well as interesting spin polarization. Chiral nanocarbons have attracted growing attention due to their exotic 3D structure, inherent chirality, and intriguing optoelectronic properties, in particular, their unique chiral-induced spin selectivity (CISS) effect. Due to the unique structural tunability and the specificity of quantum sensing, chiral nanocarbons have the potential to be a transformative tool in the next generation of quantum applications. Among them, helical nanographenes (NGs) featuring multi-layer topology have been considered as promising candidates for understanding the intricate interplay between the chiral structure and chiroptical properties/spin polarization. Herein, we demonstrate the modular synthetic strategy to construct a series of novel helical NGs with bilayer, trilayer, and tetralayer structures. The resultant NGs exhibit excellent circular dichroism (CD) and circularly polarized luminescence (CPL) responses with unprecedented high CPL brightness, rendering them promising candidates for CPL emitters. More interestingly, with the cooperation with Prof. Ron Naaman’s group, the magnetoresistance (MR) measurements were performed to investigate the spin polarization of our chiral molecules, which proves the clear CISS effect of our helical NGs.


Brief CV

Dr. Wenhui Niu studied polymer engineering at Sichuan University and obtained her Bachelor’s degree in 2016. From 2016, she started her PhD in chemistry from Shanghai Jiao Tong University under the supervision of Prof. Yiyong Mai. Between 2017 and 2020, she joined Prof. Xinliang Feng’s group as an exchange PhD student. In 2021, she received her PhD degree and joined the group of Prof. Xinliang Feng and continued her academic research as a postdoctoral fellow at Technische Universität Dresden for one year. In 2022, she joined the Max Planck Institute of Microstructure Physics and she was appointed as research group leader of “Quantum Chiral Nanocarbons” subgroup, where she focuses on the exploitation of novel chiral nanographenes with excellent chiroptical properties and unique spin polarization. In 2023, she received the Minerva Fast Track fellowship from the Max Planck Society.



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