title: Line printing solution-processable small molecules with uniform surface profile via ink-jet printer.
abstract: Line printing offers a feasible approach to remove the pixel well structure which is widely used to confine the ink-jet printed solution. In the study, a uniform line is printed by an ink-jet printer. To achieve a uniform surface profile of the printed line, 10vol% low-volatile solvent DMA (3,4-Dimethylanisole) is mixed with high-volatile solvent Pxy (p-xylene) as the solvent. After a solution-processable small molecule is dissolved, the surface tension of DMA solution becomes lower than that of Pxy solution, which creates an inward Marangoni flow during the solvent evaporation. The inward Marangoni flow balances out the outward capillary flow, thereby forming a flat film surface. The line width of the printed line depends on the contact angle of the solution on the hole injection layer.
authors.affiliation: Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, State Key Laboratory of Luminescent Materials and Devices, Guangzhou 510640, PR China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, State Key Laboratory of Luminescent Materials and Devices, Guangzhou 510640, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, State Key Laboratory of Luminescent Materials and Devices, Guangzhou 510640, PR China.
authors.forename: Wanyi
authors.initials: W
authors.lastname: Tan
authors.affiliation: Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, State Key Laboratory of Luminescent Materials and Devices, Guangzhou 510640, PR China.
authors.forename: Xuhui
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, State Key Laboratory of Luminescent Materials and Devices, Guangzhou 510640, PR China. Electronic address: jianwang@scut.edu.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, State Key Laboratory of Luminescent Materials and Devices, Guangzhou 510640, PR China. Electronic address: psjbpeng@scut.edu.cn.
authors.forename: Junbiao
authors.initials: J
authors.lastname: Peng
authors.affiliation: Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, State Key Laboratory of Luminescent Materials and Devices, Guangzhou 510640, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Cao
keywords: Coffee ring; Ink-jet printing; Small molecular; Solution process; Surface tension