Abstract
Interfacial chemistry at organic-inorganic contact critically determines the function of a wide range of molecular and organic electronic devices and other systems. The chemistry is, however, difficult to understand due to the lack of easily accessible in-operando spectroscopic techniques that permit access to interfacial structure on a molecular scale. Herein, we compare two analogous junctions formed with identical organic thin film and different liquid top-contacts (water droplet vs eutectic gallium indium alloy) and elucidate the puzzling interfacial characteristics. Specifically, we fine-tune the surface topography of the organic surface using mixed self-assembled monolayers (SAMs): single component SAM composed of rectifier (2,2′-bipyridyl-terminated n-undecanethiolate; denoted as SC11BIPY) is systematically diluted with nonrectifying n-alkanethiolates of different lengths (denoted as SCn where n = 8, 10, 12, 14, 16, 18). Characterization of the resulting mixed SAMs in wettability and tunneling currents with the two separate liquid top-contacts allows us to investigate the role of phase segregation and gauche defect in the SAM//liquid interfaces. The results reported here show the difference in length between SC11BIPY and SCn is translated into nanoscopic pits and gauche-conformer defects on the surface, and the difference in contact force - hydrostatic vs user pressures - and hence conformity of contact account for the difference in wettability and rectification behaviors. Our work provides an insight into the role of molecule-electrode interfacial defects in performance of molecular-scale electronic devices.
| Original language | English |
|---|---|
| Pages (from-to) | 12303-12307 |
| Number of pages | 5 |
| Journal | Journal of the American Chemical Society |
| Volume | 140 |
| Issue number | 38 |
| DOIs | |
| Publication status | Published - 2018 Sep 26 |
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ASJC Scopus subject areas
- Catalysis
- Chemistry(all)
- Biochemistry
- Colloid and Surface Chemistry
Cite this
Elucidating the Role of Molecule-Electrode Interfacial Defects in Charge Tunneling Characteristics of Large-Area Junctions. / Kong, Gyu Don; Jin, Junji; Thuo, Martin; Song, Hyunsun; Joung, Joonyoung F.; Park, Sungnam; Yoon, Hyo Jae.
In: Journal of the American Chemical Society, Vol. 140, No. 38, 26.09.2018, p. 12303-12307.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Elucidating the Role of Molecule-Electrode Interfacial Defects in Charge Tunneling Characteristics of Large-Area Junctions
AU - Kong, Gyu Don
AU - Jin, Junji
AU - Thuo, Martin
AU - Song, Hyunsun
AU - Joung, Joonyoung F.
AU - Park, Sungnam
AU - Yoon, Hyo Jae
PY - 2018/9/26
Y1 - 2018/9/26
N2 - Interfacial chemistry at organic-inorganic contact critically determines the function of a wide range of molecular and organic electronic devices and other systems. The chemistry is, however, difficult to understand due to the lack of easily accessible in-operando spectroscopic techniques that permit access to interfacial structure on a molecular scale. Herein, we compare two analogous junctions formed with identical organic thin film and different liquid top-contacts (water droplet vs eutectic gallium indium alloy) and elucidate the puzzling interfacial characteristics. Specifically, we fine-tune the surface topography of the organic surface using mixed self-assembled monolayers (SAMs): single component SAM composed of rectifier (2,2′-bipyridyl-terminated n-undecanethiolate; denoted as SC11BIPY) is systematically diluted with nonrectifying n-alkanethiolates of different lengths (denoted as SCn where n = 8, 10, 12, 14, 16, 18). Characterization of the resulting mixed SAMs in wettability and tunneling currents with the two separate liquid top-contacts allows us to investigate the role of phase segregation and gauche defect in the SAM//liquid interfaces. The results reported here show the difference in length between SC11BIPY and SCn is translated into nanoscopic pits and gauche-conformer defects on the surface, and the difference in contact force - hydrostatic vs user pressures - and hence conformity of contact account for the difference in wettability and rectification behaviors. Our work provides an insight into the role of molecule-electrode interfacial defects in performance of molecular-scale electronic devices.
AB - Interfacial chemistry at organic-inorganic contact critically determines the function of a wide range of molecular and organic electronic devices and other systems. The chemistry is, however, difficult to understand due to the lack of easily accessible in-operando spectroscopic techniques that permit access to interfacial structure on a molecular scale. Herein, we compare two analogous junctions formed with identical organic thin film and different liquid top-contacts (water droplet vs eutectic gallium indium alloy) and elucidate the puzzling interfacial characteristics. Specifically, we fine-tune the surface topography of the organic surface using mixed self-assembled monolayers (SAMs): single component SAM composed of rectifier (2,2′-bipyridyl-terminated n-undecanethiolate; denoted as SC11BIPY) is systematically diluted with nonrectifying n-alkanethiolates of different lengths (denoted as SCn where n = 8, 10, 12, 14, 16, 18). Characterization of the resulting mixed SAMs in wettability and tunneling currents with the two separate liquid top-contacts allows us to investigate the role of phase segregation and gauche defect in the SAM//liquid interfaces. The results reported here show the difference in length between SC11BIPY and SCn is translated into nanoscopic pits and gauche-conformer defects on the surface, and the difference in contact force - hydrostatic vs user pressures - and hence conformity of contact account for the difference in wettability and rectification behaviors. Our work provides an insight into the role of molecule-electrode interfacial defects in performance of molecular-scale electronic devices.
UR - http://www.scopus.com/inward/record.url?scp=85053541176&partnerID=8YFLogxK
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U2 - 10.1021/jacs.8b08146
DO - 10.1021/jacs.8b08146
M3 - Article
C2 - 30183277
AN - SCOPUS:85053541176
VL - 140
SP - 12303
EP - 12307
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 38
ER -