Stabilization of discotic liquid organic thin films by ITO surface treatment

被引:25
作者
Archambeau, S.
Seguy, I.
Jolinat, P.
Farenc, J.
Destruel, P. [1 ]
Nguyen, T. P.
Bock, H.
Grelet, E.
机构
[1] Univ Toulouse 3, Lab Genie Elect Toulouse, F-31062 Toulouse 09, France
[2] Univ Nantes, CNRS, Inst Mat Jean Rouxel, F-44322 Nantes, France
[3] Univ Bordeaux 1, Ctr Rech Paul Pascal, CNRS, F-33600 Pessac, France
关键词
discotic liquid crystal; dewetting; ITO treatments; XPS;
D O I
10.1016/j.apsusc.2006.04.004
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Discotic liquid crystals (LCs) are promising materials in the field of electronic components and, in particular, to make efficient photovoltaic cells due to their good charge transport properties. These materials generally exhibit a mesophase in which the disk-shaped molecules can self-assemble into columns, which favorize charge displacement, and may align themselves uniformly on surfaces to form well-oriented thin films. In order to orientate such a columnar thin film on an indium tin oxide (ITO) substrate, the film is heated up to the temperature range of the isotropic liquid phase and subsequently cooled down again. This treatment may lead not only to the desired alignment, but also to dewetting, which leads to an appreciable inhomogeneity in film thickness and to short circuits during the realization of photovoltaic cells. In this article, we describe how this dewetting and the film morphology can be influenced by ITO surface treatments. The chemical modifications of the surface by these treatments were studied by X-ray photoelectron spectroscopy (XPS). Such ITO treatments are shown to be efficient to prevent thin film dewetting when combined with rapid cooling through the isotropic-to-LC phase transition. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:2078 / 2086
页数:9
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