יום ראשון, ה – 16 ביולי 2023 בשעה 14:30
Zoom link: https://technion.zoom.us/j/93818286607
Mr. Yuhong Chen – MSc candidate
Department of Materials Science and Engineering
GTIIT-Technion MSc Student in Material Science and Engineering
The lecture will take place on Sunday, Jul 16th, 2023 at 14:30
Zoom link: https://technion.zoom.us/j/93818286607
This seminar reports a combined experimental and theoretical investigation of the transport properties of molecular junctions based on alkane alkynes (CnA) with varying lengths (n) and metal electrodes (Ag, Au, and Pt) with different work functions (Φ) using CP-AFM. The work function dependence of conductivity clearly indicates that HOMO-assisted transport occurs in the case of CnA. The weak dependence of tunneling barrier 𝜀𝜀ℎ on both n and Φ suggests that the transport dependence on n and Φ is primarily governed by the molecule-electrode interface coupling (Γ). Furthermore, the investigation reveals that the HOMO position of CnA is located at the interface linker between the metal substrate and the molecular backbone. Importantly, our independent measurements of the HOMO-Fermi offset of CnA SAMs by UPS provide values of 𝜀𝜀ℎ𝑢𝑢𝑢𝑢𝑢𝑢 that agree with the transport estimates 𝜀𝜀ℎ 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡 remarkably. The findings further support the HOMO-assisted transport in the case of CnA. In addition, the conductance and the electronic structures were found to be comparable between the junctions made of alkyl thiols (CnT) and alkane alkynes (CnA). This demonstrates that ethynyl groups can be used as one of the ideal linkers for fabricating excellent and stable molecular junctions.
BIO
Yuhong Chen is currently a 2nd year MSc student in Material Science and Engineering at Technion Israel Institute of Technology and Guangdong Technion Israel Institute of Technology. He obtained his BSc degree from Technion Israel Institute of Technology and Guangdong Technion Israel Institute of Technology in 2021. Since then, he has been studying the electronic structures of molecular junctions based on alkane alkyne towards his master degree.