Formation of aligned periodic patterns during the crystallization of organic semiconductor thin films
Formation of aligned periodic patterns during the crystallization of organic semiconductor thin films
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DOI：
10.1038/s41563-019-0379-3
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发表时间：
2019-07-01
期刊：
影响因子：
41.2
通讯作者：
Holmes, Russell J.
中科院分区：
文献类型：
--
作者：
Bangsund, John S.;Fielitz, Thomas R.;Holmes, Russell J.
具有微米尺度特征的自组织图案在大面积制备光子器件和光电子散射层方面具有广阔的应用前景。图案形成将理想地发生在有源半导体中，以避免需要进一步的处理步骤。在这里，我们报告了一种通过简单的退火过程在单层有机半导体中形成周期性图案的方法。当加热时，结晶前沿在薄膜上传播，产生正弦表面结构，其波长与近红外光相当。这些表面特征最初形成在一微米的晶体生长前沿的非晶区域内，可能是由于晶体生长和表面质量传输之间的竞争。通过改变薄膜厚度和退火温度，图案波长可以在800 nm ~ 2,400 nm范围内调节，得到毫米级的畴尺寸。这一现象可用于微结构有机光电器件的自组装。
Self-organizing patterns with micrometre-scale features are promising for the large-area fabrication of photonic devices and scattering layers in optoelectronics. Pattern formation would ideally occur in the active semiconductor to avoid the need for further processing steps. Here, we report an approach to form periodic patterns in single layers of organic semiconductors by a simple annealing process. When heated, a crystallization front propagates across the film, producing a sinusoidal surface structure with wavelengths comparable to that of near-infrared light. These surface features initially form in the amorphous region within a micrometre of the crystal growth front, probably due to competition between crystal growth and surface mass transport. The pattern wavelength can be tuned from 800 nm to 2,400 nm by varying the film thickness and annealing temperature, and millimetre-scale domain sizes are obtained. This phenomenon could be exploited for the self-assembly of microstructured organic optoelectronic devices.