Awsiuk Kamil, Dąbczyński Paweł, Marzec Mateusz M, Rysz Jakub, Moons Ellen, Budkowski Andrzej
Marian Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Krakow, Poland.
Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow, Poland.
Materials (Basel). 2022 Mar 17;15(6):2219. doi: 10.3390/ma15062219.
Domains rich in different blend components phase-separate during deposition, creating a film morphology that determines the performance of active layers in organic electronics. However, morphological control either relies on additional fabrication steps or is limited to a small region where an external interaction is applied. Here, we show that different semiconductor-insulator polymer composites can be rapidly dip-coated with the film structure electrically switched between distinct morphologies during deposition guided by the meniscus formed between the stationary barrier and horizontally drawn solid substrate. Reversible and repeatable changes between the morphologies used in devices, e.g., lateral morphologies and stratified layers of semiconductors and insulators, or between phase-inverted droplet-like structures are manifested only for one polarity of the voltage applied across the meniscus as a rectangular pulse. This phenomenon points to a novel mechanism, related to voltage-induced doping and the doping-dependent solubility of the conjugated polymer, equivalent to an increased semiconductor content that controls the composite morphologies. This is effective only for the positively polarized substrate rather than the barrier, as the former entrains the nearby lower part of the coating solution that forms the final composite film. The mechanism, applied to the pristine semiconductor solution, results in an increased semiconductor deposition and 40-times higher film conductance.
富含不同混合成分的区域在沉积过程中会发生相分离，形成一种薄膜形态，这种形态决定了有机电子器件中活性层的性能。然而，形态控制要么依赖于额外的制造步骤，要么局限于施加外部相互作用的小区域。在此，我们展示了不同的半导体 - 绝缘体聚合物复合材料可以通过快速浸涂制备，在由固定阻挡层和水平拉伸的固体基板之间形成的弯月面引导的沉积过程中，薄膜结构能够在不同形态之间进行电切换。器件中使用的形态之间的可逆和可重复变化，例如半导体和绝缘体的横向形态以及分层结构，或者在相反转的液滴状结构之间的变化，仅在以矩形脉冲形式施加在弯月面上的电压的一个极性下才会显现。这种现象指向一种新机制，该机制与电压诱导掺杂以及共轭聚合物的掺杂依赖性溶解度有关，等同于增加了控制复合形态的半导体含量。这仅对带正电的基板有效，而不是对阻挡层有效，因为前者夹带了形成最终复合膜的涂层溶液的附近下部。将该机制应用于原始半导体溶液，会导致半导体沉积增加以及薄膜电导率提高40倍。
