TY - JOUR
T1 - Study of local structure at crystalline rubrene grain boundaries via scanning transmission X-ray microscopy
AU - Foggiatto, Alexandre L.
AU - Takeichi, Yasuo
AU - Ono, Kanta
AU - Suga, Hiroki
AU - Takahashi, Yoshio
AU - Fusella, Michael A.
AU - Dull, Jordan T.
AU - Rand, Barry P.
AU - Kutsukake, Kentaro
AU - Sakurai, Takeaki
N1 - Funding Information:
A.L.F. acknowledges the Japanese Government for providing financial assistance to conduct this work through Monbukagakusho (MEXT) scholarship. M.A.F, J.T.D., and B.P.R. acknowledge funding from the National Science Foundation , award no. ECCS-1709222 . This work was supported by JSPS Grants-in-Aid for Scientific Research 16K04943 and it was performed under the approval of the Photon Factory Program Advisory Committee (Proposal No. 2016S2-003 ).
Funding Information:
A.L.F. acknowledges the Japanese Government for providing financial assistance to conduct this work through Monbukagakusho (MEXT) scholarship. M.A.F, J.T.D. and B.P.R. acknowledge funding from the National Science Foundation, award no. ECCS-1709222. This work was supported by JSPS Grants-in-Aid for Scientific Research 16K04943 and it was performed under the approval of the Photon Factory Program Advisory Committee (Proposal No. 2016S2-003).
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/11
Y1 - 2019/11
N2 - Rubrene is a promising and archetypal organic semiconductor owing to its high reported hole mobility. However, this high mobility only exists in its crystalline state, with orders of magnitude reduction in disordered films. Thus, as it pertains to thin film polycrystalline rubrene, it is important to understand structure and the presence of disordered regions at grain boundaries. Here, we use scanning transmission X-ray microscopy (STXM) to investigate polycrystalline rubrene thin films with either platelet or spherulite morphology. The STXM images allow us to distinguish and quantify the arrangement of the local structure in the crystal. The analysis suggests that the platelet film has more oriented molecules in the crystal than in the spherulite phase. Also, at spherulite grain boundaries, we reveal a high number of misaligned molecules compared to the smooth boundary in the platelet case, with grain boundary sinuosity of 0.045 ± 0.002 and 0.139 ± 0.002 μm for the platelet and spherulite cases, respectively, which help to explain the higher mobility in the former case.
AB - Rubrene is a promising and archetypal organic semiconductor owing to its high reported hole mobility. However, this high mobility only exists in its crystalline state, with orders of magnitude reduction in disordered films. Thus, as it pertains to thin film polycrystalline rubrene, it is important to understand structure and the presence of disordered regions at grain boundaries. Here, we use scanning transmission X-ray microscopy (STXM) to investigate polycrystalline rubrene thin films with either platelet or spherulite morphology. The STXM images allow us to distinguish and quantify the arrangement of the local structure in the crystal. The analysis suggests that the platelet film has more oriented molecules in the crystal than in the spherulite phase. Also, at spherulite grain boundaries, we reveal a high number of misaligned molecules compared to the smooth boundary in the platelet case, with grain boundary sinuosity of 0.045 ± 0.002 and 0.139 ± 0.002 μm for the platelet and spherulite cases, respectively, which help to explain the higher mobility in the former case.
KW - Image analysis
KW - Organic semiconductor
KW - Rubrene
KW - X-ray microscope
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U2 - 10.1016/j.orgel.2019.07.021
DO - 10.1016/j.orgel.2019.07.021
M3 - Article
AN - SCOPUS:85069913560
SN - 1566-1199
VL - 74
SP - 315
EP - 320
JO - Organic Electronics: physics, materials, applications
JF - Organic Electronics: physics, materials, applications
ER -