TY - JOUR
T1 - Elucidating the Coordination of Diethyl Sulfide Molecules in Copper(I) Thiocyanate (CuSCN) Thin Films and Improving Hole Transport by Antisolvent Treatment
AU - Worakajit, Pimpisut
AU - Hamada, Fumiya
AU - Sahu, Debashis
AU - Kidkhunthod, Pinit
AU - Sudyoadsuk, Taweesak
AU - Promarak, Vinich
AU - Harding, David J.
AU - Packwood, Daniel M.
AU - Saeki, Akinori
AU - Pattanasattayavong, Pichaya
N1 - Funding Information:
P.W. and P.P. would like to acknowledge funding from Vidyasirimedhi Institute of Science and Technology (VISTEC) and support of scientific instruments from VISTEC's Frontier Research Center (FRC). P.P. gratefully acknowledges the grant TRG6280013 jointly funded by Thailand's Synchrotron Light Research Institute (SLRI) and Thailand Research Fund (TRF). The support for collaborative research between VISTEC and iCeMS is also highly appreciated. A.S. acknowledges the KAKENHI Grant‐in‐Aid for Scientific Research (A) (Grant No. JP16H02285) from the Japan Society for the Promotion of Science (JSPS). The authors also thank Prof. Itaru Osaka at Hiroshima University and Dr. Tomoyuki Koganezawa at Japan Synchrotron Radiation Research Institute (JASRI) for the support of 2D GIXRD experiments at SPring‐8 (2019A1765).
Funding Information:
P.W. and P.P. would like to acknowledge funding from Vidyasirimedhi Institute of Science and Technology (VISTEC) and support of scientific instruments from VISTEC's Frontier Research Center (FRC). P.P. gratefully acknowledges the grant TRG6280013 jointly funded by Thailand's Synchrotron Light Research Institute (SLRI) and Thailand Research Fund (TRF). The support for collaborative research between VISTEC and iCeMS is also highly appreciated. A.S. acknowledges the KAKENHI Grant-in-Aid for Scientific Research (A) (Grant No. JP16H02285) from the Japan Society for the Promotion of Science (JSPS). The authors also thank Prof. Itaru Osaka at Hiroshima University and Dr. Tomoyuki Koganezawa at Japan Synchrotron Radiation Research Institute (JASRI) for the support of 2D GIXRD experiments at SPring-8 (2019A1765).
Publisher Copyright:
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/9/1
Y1 - 2020/9/1
N2 - Copper(I) thiocyanate (CuSCN) is rising to prominence as a hole-transporting semiconductor in various opto/electronic applications. Its unique combination of good hole mobility, high optical transparency, and solution-processability renders it a promising hole-transport layer for solar cells and p-type channel in thin-film transistors. CuSCN is typically deposited from sulfide-based solutions with diethyl sulfide (DES) being the most widely used. However, little is known regarding the effects of DES on CuSCN films despite the fact that DES can coordinate with Cu(I) and result in a different coordination polymer having a distinct crystal structure when fully coordinated. Herein, the coordination of DES in CuSCN films is thoroughly investigated with a suite of characterization techniques as well as density functional theory. This study reveals that DES directly affects the microstructure of CuSCN by stabilizing the polar crystalline surfaces via the formation of strong coordination bonds. Furthermore, a simple antisolvent treatment is demonstrated to be effective at modifying the microstructure and morphology of CuSCN films. The treatment with tetrahydrofuran or acetone leads to uniform films consisting of CuSCN crystallites with high crystallinity and their surfaces passivated by DES molecules, resulting in an increase in the hole mobility from 0.01 to 0.05 cm2 V−1 s−1.
AB - Copper(I) thiocyanate (CuSCN) is rising to prominence as a hole-transporting semiconductor in various opto/electronic applications. Its unique combination of good hole mobility, high optical transparency, and solution-processability renders it a promising hole-transport layer for solar cells and p-type channel in thin-film transistors. CuSCN is typically deposited from sulfide-based solutions with diethyl sulfide (DES) being the most widely used. However, little is known regarding the effects of DES on CuSCN films despite the fact that DES can coordinate with Cu(I) and result in a different coordination polymer having a distinct crystal structure when fully coordinated. Herein, the coordination of DES in CuSCN films is thoroughly investigated with a suite of characterization techniques as well as density functional theory. This study reveals that DES directly affects the microstructure of CuSCN by stabilizing the polar crystalline surfaces via the formation of strong coordination bonds. Furthermore, a simple antisolvent treatment is demonstrated to be effective at modifying the microstructure and morphology of CuSCN films. The treatment with tetrahydrofuran or acetone leads to uniform films consisting of CuSCN crystallites with high crystallinity and their surfaces passivated by DES molecules, resulting in an increase in the hole mobility from 0.01 to 0.05 cm2 V−1 s−1.
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U2 - 10.1002/adfm.202002355
DO - 10.1002/adfm.202002355
M3 - Article
AN - SCOPUS:85087207942
SN - 1616-301X
VL - 30
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 36
M1 - 2002355
ER -