Abstract
Ligand exchange is an advanced technique for tuning the various properties of nanocrystal (NC) thin films, widely used in the NC thin-film device applications. Understanding how the NC thin films transform into functional thin-film devices upon ligand exchange is essential. Here, we investigated the process of structural transformation and accompanying property changes in the NC thin films, by monitoring the various characteristics of silver (Ag) NC thin films at each stage of the ligand-exchange process. A transition state was identified in which the ligands are partially exchanged, where the NC thin films showed unexpected electromechanical features with high gauge factors up to 300. A model system was established to explain the origin of the high gauge factors, supported by the observation of spontaneously formed nanocracks and metal-insulator transition from the structural analysis and charge transport study, respectively. Taking advantages of the unique electromechanical properties of the NC thin films, we fabricated flexible strain gauge sensor devices with high sensitivity, reliability, and stability. We introduce a one-step fabrication process, namely, "the time- and spatial-selective ligand-exchange process", for the design of low-cost and high-performance wearable sensors that effectively detect human motion, such as finger or neck muscle movement. This study provides a fundamental understanding of the ligand-exchange process in NCs, as well as an insight into the functionalities of the NC thin films for technological applications.
| Original language | English |
|---|---|
| Pages (from-to) | 25502-25510 |
| Number of pages | 9 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 10 |
| Issue number | 30 |
| DOIs | |
| Publication status | Published - 2018 Aug 1 |
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Keywords
- intermediate state
- ligand exchange
- metal-insulator transition
- nanocrystals
- strain gauge
- structural transformation
- wearable sensor
ASJC Scopus subject areas
- Materials Science(all)
Cite this
Transition States of Nanocrystal Thin Films during Ligand-Exchange Processes for Potential Applications in Wearable Sensors. / Lee, Seung Wook; Joh, Hyungmok; Seong, Mingi; Lee, Woo Seok; Choi, Ji Hyuk; Oh, Soong Ju.
In: ACS Applied Materials and Interfaces, Vol. 10, No. 30, 01.08.2018, p. 25502-25510.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Transition States of Nanocrystal Thin Films during Ligand-Exchange Processes for Potential Applications in Wearable Sensors
AU - Lee, Seung Wook
AU - Joh, Hyungmok
AU - Seong, Mingi
AU - Lee, Woo Seok
AU - Choi, Ji Hyuk
AU - Oh, Soong Ju
PY - 2018/8/1
Y1 - 2018/8/1
N2 - Ligand exchange is an advanced technique for tuning the various properties of nanocrystal (NC) thin films, widely used in the NC thin-film device applications. Understanding how the NC thin films transform into functional thin-film devices upon ligand exchange is essential. Here, we investigated the process of structural transformation and accompanying property changes in the NC thin films, by monitoring the various characteristics of silver (Ag) NC thin films at each stage of the ligand-exchange process. A transition state was identified in which the ligands are partially exchanged, where the NC thin films showed unexpected electromechanical features with high gauge factors up to 300. A model system was established to explain the origin of the high gauge factors, supported by the observation of spontaneously formed nanocracks and metal-insulator transition from the structural analysis and charge transport study, respectively. Taking advantages of the unique electromechanical properties of the NC thin films, we fabricated flexible strain gauge sensor devices with high sensitivity, reliability, and stability. We introduce a one-step fabrication process, namely, "the time- and spatial-selective ligand-exchange process", for the design of low-cost and high-performance wearable sensors that effectively detect human motion, such as finger or neck muscle movement. This study provides a fundamental understanding of the ligand-exchange process in NCs, as well as an insight into the functionalities of the NC thin films for technological applications.
AB - Ligand exchange is an advanced technique for tuning the various properties of nanocrystal (NC) thin films, widely used in the NC thin-film device applications. Understanding how the NC thin films transform into functional thin-film devices upon ligand exchange is essential. Here, we investigated the process of structural transformation and accompanying property changes in the NC thin films, by monitoring the various characteristics of silver (Ag) NC thin films at each stage of the ligand-exchange process. A transition state was identified in which the ligands are partially exchanged, where the NC thin films showed unexpected electromechanical features with high gauge factors up to 300. A model system was established to explain the origin of the high gauge factors, supported by the observation of spontaneously formed nanocracks and metal-insulator transition from the structural analysis and charge transport study, respectively. Taking advantages of the unique electromechanical properties of the NC thin films, we fabricated flexible strain gauge sensor devices with high sensitivity, reliability, and stability. We introduce a one-step fabrication process, namely, "the time- and spatial-selective ligand-exchange process", for the design of low-cost and high-performance wearable sensors that effectively detect human motion, such as finger or neck muscle movement. This study provides a fundamental understanding of the ligand-exchange process in NCs, as well as an insight into the functionalities of the NC thin films for technological applications.
KW - intermediate state
KW - ligand exchange
KW - metal-insulator transition
KW - nanocrystals
KW - strain gauge
KW - structural transformation
KW - wearable sensor
UR - http://www.scopus.com/inward/record.url?scp=85049648120&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85049648120&partnerID=8YFLogxK
U2 - 10.1021/acsami.8b06754
DO - 10.1021/acsami.8b06754
M3 - Article
C2 - 29968456
AN - SCOPUS:85049648120
VL - 10
SP - 25502
EP - 25510
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 30
ER -