TY - JOUR
T1 - Raman spectroscopy applied to reveal polycrystalline grain structures and carrier transport properties of organic semiconductor films
T2 - Application to pentacene-based organic transistors
AU - Cheng, Horng Long
AU - Liang, Xin Wei
AU - Chou, Wei Yang
AU - Mai, Yu Shen
AU - Yang, Chou Yu
AU - Chang, Li Ren
AU - Tang, Fu Ching
N1 - Funding Information:
This work was supported by the National Science Council, Taiwan, through Grant NSC 97-2221-E-006-245 and NSC 96-2112-M-006-015-MY3. We are grateful to the National Center for High-performance Computing of Taiwan for computer time and facilities. The authors acknowledge J.M. Chen for the technical support and helpful discussion during the XRD measurements.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2009/4
Y1 - 2009/4
N2 - We have fabricated high performance polycrystalline pentacene-based thin-film transistors using several dielectrics with different surface properties, including inorganic oxide and polymeric materials. These materials provide excellent samples for the analysis of charge transport properties, particularly the impact of the grain boundary and the molecular structural quality within the grain on the efficient charge transport. The carrier transport in polycrystalline organic films with grain structures is often interpreted using the grain boundary model. Assuming a large amount of charges are trapped at the boundaries, the model neglects the microstructural quality inside a grain. According to joint experimental and theoretical Raman spectra and normal modes analysis on these pentacene films, we present a new observation that the microscopic hopping transport parameters, i.e., intermolecular interactions and reorganization energy, in polycrystalline films govern the carrier transport. An obvious, positive correlation is found between the mobility and the molecular vibrational characteristics, especially the intermolecular vibrational coupling energy, under all varieties of grain size morphology. MicroRaman mapping methodology reveals that the grain size of pentacene films should not be taken for granted in structural quality and efficient charge transport. The microstructural qualities inside the grain play an important role in efficient charge transport.
AB - We have fabricated high performance polycrystalline pentacene-based thin-film transistors using several dielectrics with different surface properties, including inorganic oxide and polymeric materials. These materials provide excellent samples for the analysis of charge transport properties, particularly the impact of the grain boundary and the molecular structural quality within the grain on the efficient charge transport. The carrier transport in polycrystalline organic films with grain structures is often interpreted using the grain boundary model. Assuming a large amount of charges are trapped at the boundaries, the model neglects the microstructural quality inside a grain. According to joint experimental and theoretical Raman spectra and normal modes analysis on these pentacene films, we present a new observation that the microscopic hopping transport parameters, i.e., intermolecular interactions and reorganization energy, in polycrystalline films govern the carrier transport. An obvious, positive correlation is found between the mobility and the molecular vibrational characteristics, especially the intermolecular vibrational coupling energy, under all varieties of grain size morphology. MicroRaman mapping methodology reveals that the grain size of pentacene films should not be taken for granted in structural quality and efficient charge transport. The microstructural qualities inside the grain play an important role in efficient charge transport.
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U2 - 10.1016/j.orgel.2008.12.002
DO - 10.1016/j.orgel.2008.12.002
M3 - Article
AN - SCOPUS:63749093581
SN - 1566-1199
VL - 10
SP - 289
EP - 298
JO - Organic Electronics
JF - Organic Electronics
IS - 2
ER -