Abstract
The formation and surface structures of cyclohexanethiolate (CYH-S) and cyclohexaneselenolate (CYH-Se) self-assembled monolayers (SAMs) on Au(1 1 1) were probed to understand headgroup effects on the formation of SAMs with an alicyclic backbone using scanning tunneling microscopy (STM). CYH-S SAMs on Au(1 1 1) formed via solution deposition at room temperature (RT) were composed of small ordered domains with sizes ranging from 10 to 30 nm, whereas CYH-Se SAMs on Au(1 1 1) usually had a disordered phase. The molecular arrangements of CYH-S SAMs on Au(1 1 1) could be described as a (5 × 2√3)R30° structure. CYH-Se SAMs formed via vapor deposition at RT had a long-range ordered phase (greater than 100 nm) including missing rows and molecular defects. A highly ordered crystalline phase of CYH-Se SAMs on Au(1 1 1) with fewer structural defects was formed at 323 K for 12 h that was assigned to a (√3.5 × 2√10)R27° structure. STM observations revealed that the domain formation and surface structures of CYH-Se SAMs on Au(1 1 1) were completely different from those of CYH-S SAMs. Furthermore, we found that CYH-S and CYH-Se SAM can be utilized for bonding-induced work function modification of Au substrate through Kelvin probe force microscopy measurement.
Original language | English |
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Article number | 151454 |
Journal | Applied Surface Science |
Volume | 572 |
DOIs | |
Publication status | Published - 2022 Jan 15 |
Bibliographical note
Funding Information:This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education ( NRF-2012R1A6A1029029, NRF-2018R1D1A1B07048063, NRF-2020R1A6A1A06046728 , and NRF-2021R1A2C2010917 for J. Noh; NRF-2019R1A2C2011003 and NRF-2021M3F3A2A03017999 for H. J. Yoon). A part of this work was also supported by a Scientific Research on Innovative Areas Grant Number JP20H05210 from JSPS.
Publisher Copyright:
© 2021 Elsevier B.V.
Keywords
- Cyclohexaneselenolate
- Cyclohexanethiolate
- Domain formation
- Scanning tunneling microscopy
- Self-assembled monolayers
- Surface structure
ASJC Scopus subject areas
- Chemistry(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films